Crispr enzymes and systems

This application is a national phase entry of International Application No. PCT/US2017/047459 filed Aug. 17, 2017, which claims the benefit of U.S. Provisional Application No. 62/376,372 filed Aug. 17, 2016, and U.S. Provisional Application No. 62/437,023 filed Dec. 20, 2016.

This invention was made with government support under grant numbers MH100706 and MH110049 awarded by the National Institutes of Health. The government has certain rights in the invention.

The contents of the electronic sequence listing (“BROD-0961US_Corrected_2020-10-01_ST25.txt”; Size is 125,525 bytes; was created on Oct. 1, 2020) is herein incorporated by reference in its entirety.

The present invention generally relates to systems, methods and compositions related to Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and components thereof. The present invention also generally relates to delivery of large payloads and includes novel delivery particles, particularly using lipid and viral particle, and also novel viral capsids, both suitable to deliver large payloads, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), CRISPR protein (e.g., Cas, Cas9, Cpf1, Cas13a, Cas13b and the like), CRISPR-Cas or CRISPR system or CRISPR-Cas complex, components thereof, nucleic acid molecules, e.g., vectors, involving the same and uses of all of the foregoing, amongst other aspects. Additionally, the present invention relates to methods for developing or designing CRISPR-Cas system based therapy or therapeutics.

Recent advances in genome sequencing techniques and analysis methods have significantly accelerated the ability to catalog and map genetic factors associated with a diverse range of biological functions and diseases. Precise genome targeting technologies are needed to enable systematic reverse engineering of causal genetic variations by allowing selective perturbation of individual genetic elements, as well as to advance synthetic biology, biotechnological, and medical applications. Although genome-editing techniques such as designer zinc fingers, transcription activator-like effectors (TALEs), or homing meganucleases are available for producing targeted genome perturbations, there remains a need for new genome engineering technologies that employ novel strategies and molecular mechanisms and are affordable, easy to set up, scalable, and amenable to targeting multiple positions within the eukaryotic genome. This would provide a major resource for new applications in genome engineering and biotechnology.

The CRISPR-Cas systems of bacterial and archaeal adaptive immunity show extreme diversity of protein composition and genomic loci architecture. The CRISPR-Cas system loci has more than 50 gene families and there is no strictly universal genes indicating fast evolution and extreme diversity of loci architecture. So far, adopting a multi-pronged approach, there is comprehensive cas gene identification of about 395 profiles for 93 Cas proteins. Classification includes signature gene profiles plus signatures of locus architecture. A new classification of CRISPR-Cas systems is proposed in which these systems are broadly divided into two classes, Class 1 with multisubunit effector complexes and Class 2 with single-subunit effector modules exemplified by the Cas9 protein. Novel effector proteins associated with Class 2 CRISPR-Cas systems may be developed as powerful genome engineering tools and the prediction of putative novel effector proteins and their engineering and optimization is important.

The development of CRISPR-Cas RNA-guided endonucleases for eukaryotic genome editing has sparked intense interest in the use of this technology for therapeutic applications.

Extensive research has led to the identification of different technologies which can address the challenges of safety and efficacy. In order to allow the translation of this genome editing technologies to the clinic. There is a need for the development of an algorithm for developing a CRISPR-Cas based therapeutic, which takes into account the different variables which need to be considered.

In contrast to small molecule therapies, which target highly conserved protein active sites, treatment of disease at the genomic level must contend with significant levels of genetic variation in patient populations. Recently, large scale sequencing datasets from the Exome Aggregation Consortium (ExAC) and 1000 Genomes Project have provided an unprecedented view of the landscape of human genetic variation. This variation can affect both the efficacy of a CRISPR-based therapeutic, by disrupting the target site, and its safety, by generating off-target candidate sites.

Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.

In certain example embodiments, an engineered CRISPR-Cas effector protein that complexes with a nucleic acid comprising a guide sequence to form a CRISPR complex, and wherein in the CRISPR complex the nucleic acid molecule target one or more polynucleotide loci and the protein comprises at least one modification compared to the unmodified protein that enhances binding of the CRISPR complex to the binding site and/or alters editing preferences as compared to wildtype. The editing preference may relate to indel formation. In certain example embodiments, the at least one modification may increase formation of one or more specific indels at a target locus. The CRISPR-Cas effector protein may be Type V CRISPR-Cas effector protein. In certain example embodiments, the CRISPR-Cas protein is Cpf1 or orthologue thereof.

In certain other example embodiments, the invention is directed to vectors for delivery of the CRISPR-Cas system, including vector based systems allowing for encoding of both the effector protein and guide sequence in a single vector.

In certain other example embodiments, the invention relates to methods for developing or designing CRISPR-Cas systems. In an aspect, the present invention relates to methods for developing or designing CRISPR-Cas system based therapy or therapeutics. The present invention in particular relates to methods for improving CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. Key characteristics of successful CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics involve high specificity, high efficacy, and high safety. High specificity and high safety can be achieved among others by reduction of off-target effects.

The methods of the present invention in particular involve optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, as described herein further elsewhere. Optimization of the CRISPR-Cas system in the methods as described herein may depend on the target(s), such as the therapeutic target or therapeutic targets, the mode or type of CRISPR-Cas system modulation, such as CRISPR-Cas system based therapeutic target(s) modulation, modification, or manipulation, as well as the delivery of the CRISPR-Cas system components. One or more targets may be selected, depending on the genotypic and/or phenotypic outcome. For instance, one or more therapeutic targets may be selected, depending on (genetic) disease etiology or the desired therapeutic outcome. The (therapeutic) target(s) may be a single gene, locus, or other genomic site, or may be multiple genes, loci or other genomic sites. As is known in the art, a single gene, locus, or other genomic site may be targeted more than once, such as by use of multiple gRNAs.

These and other aspects, objects, features, and advantages of the example embodiments will become apparent to those having ordinary skill in the art upon consideration of the following detailed description of illustrated example embodiments.

FIG. 1 illustrates AsCpf1 efficiency in primary neurons. a) AAV ½ infected primary cortical cultures stained with anti-HA (AsCpf1), anti-GFP (GFP-KASH) and NeuN (Neuronal marker) antibodies. b) Surveyor assay 7 days post infection.

FIG. 2A-C illustrates Stereotactic AAV1/2 injection for AsCpf1 delivery into mouse hippocampus. a) Dissected mouse brain 3 weeks after viral delivery showing GFP fluorescence in hippocampus. b) FACS histogram of sorted GFP-KASH positive cell nuclei. c) Sorted GFP-KASH nuclei co-stained with nuclear marker Ruby Dye.

FIG. 3A-B illustrates Systemic delivery of AsCpf1 and GFP-KASH into adult mice using dual vector approach. a) Immunostaining 3 weeks after systemic tail vein injection showing delivery of Syn-GFP-KASH vector into neurons of various brain regions. b) NGS indel analysis of various brain regions dissected 3 weeks after systemic tail vein co-injection of dual vectors.

FIG. 4A-H illustrates Stereotactic injection of AAV1/2 dual vectors into adult mouse hippocampus. a) Vector design. b) Immunostaining 3 weeks after stereotactic AAV1/2 injection. c) Quantification of double infected neurons. d) Western blot showing AsCpf1 and GFP-KASH protein levels. e) NGS indel analysis 3 weeks after stereotactic injection on GFP+ sorted nuclei. f) Quantification of mono- and bi-allelic modification of Drd1 in male mice. Mecp2 and Nlgn3 are x-chromosomal genes, hence only one allele can be edited. g) Quantification of multiplex editing efficiency. h) Example NGS reads showing indels in all three targeted genes.

FIG. 5 illustrates packaging Cpf1 into a single AAV. (Top) single vector design. (bottom) Neurons express Cpf1 in nuclei and surveyor analysis shows guide RNA mediated cutting.

FIG. 6A-C illustrates a) Schematic of pLenti-Cpf1 constructs. The pLenti-Cpf1 Constructs are modified from the lentiCRISPRv2 plasmids. SpCas9 was replaced by AsCpf1 and the SpCas9 U6 guide expression cassette was replaced with a AsCpf1 U6 guide expression cassette. Unlike lentiCRISPRv2, the U6 guide expression cassette in pLenti-Cpf1 is in reverse orientation. This change was required because Cpf1 recognizes its corresponding direct repeat (DR) sequence and cleaves RNA molecules that exhibit this feature. Therefore, Lenti viral RNA is susceptible for Cpf1 mediated cleavage if it exhibits a direct repeat sequence. However, incorporating the U6 guide expression cassette in reverse order results in a RNA molecule without the direct repeat sequence. b) Surveyor assay results from two bioreps of HEK293T cells infected with pLenti-AsCpf1 carrying a single VEGFA guide and one biorep of HEK293T cells infected with pLenti-AsCpf1 encoding a DNMT1-EMX1-VEGFA-GRIN2b array. Cells were analyzed 5 days after puromycin selection. Robust cutting was observed in all lenti infected cells at the targeted loci. Red triangles indicate cleavage products. c) NGS results for DNMT1, EMX1, VEGFA, and GRIN2b from colonies grown for 10 days after single cell FACS sorting of HEK293T cells infected with pLenti-AsCpf1 encoding a DNMT1-EMX1-VEGFA-GRIN2b array. FACS was performed after 5 days of puromycin selection. Multiplex editing was observed in a subset of examined cells. Each column represent one clonal colony, blue squares indicate editing of ≥30%, while squares indicate editing <30%.

FIG. 7 illustrates lentiCRISPRv2 plasmid. Reference is made to Sanjana N E et al., Nat Methods. 2014 August; 11(8):783-4

FIG. 8 illustrates AsCpf1. Reference is made Zetsche B et al., Cell. 2015 Sep. 23. pii: S0092-8674(15)01200-3.

FIG. 9A-F depicts how human genetic variation significantly impacts the efficacy of RNA-guided endonucleases. a) Schematic illustrating the genomic target, RNA guide, and target variation. b) Fraction of residues for individual nucleotides containing variation in the ExAC dataset. c) Fraction of 2-nt PAM motifs altered by variants in the ExAC dataset. d) Percent of targets variants at different allele frequencies for each CRISPR endonuclease. e) Cumulative percent of targets containing variants for each enzyme. f) Fraction of targets containing homozygous variants at different allele frequencies. The mean and standard deviation for all enzymes is shown.

FIG. 10A-C depicts how a selection of platinum targets maximizes population efficacy. a) Schematic showing target variation within exon 2 of PCSK9-001, with regions containing high coverage in the ExAC dataset indicated (black lines below exons). b) Frequency of target variation plotted by cut site position for targets spanning the start of PCSK9-001 exon 2, with targets shown in (a) indicated by arrows. The horizontal line at 0.01% separates platinum targets (grey) from targets with high variation (red). The classification for each target is depicted below for each enzyme (grey or red boxes). c) Classification of targets for each enzyme spanning exons 2-5 of PCSK9-001.

FIG. 11A-C depicts how human genetic variation significantly impacts CRISPR endonuclease therapeutic safety. a) Schematic illustrating off-target candidates arising due to multiple different haplotypes. b) Number of off-target candidates for each CRISPR endonuclease at different allele frequencies. c) Distribution of the number of off-target candidates per platinum target for each CRISPR endonuclease.

FIG. 12A-D depicts how gene- and population-specific variation informs therapeutic design. a) Distribution of the number of off-target candidates per platinum target for 12 therapeutically relevant genes. b) Total off-target candidates for platinum targets spanning exons 2-5 of PCSK9-001 are shown for each enzyme. c) Principal component analysis (PCA) separating 1000 Genomes individuals into super populations based on patient-specific off-target profiles for platinum targets spanning 12 therapeutically relevant genes. PC2 and PC3 are shown. AFR, African; AMR, Ad mixed American; EAS, East Asian; EUR, European; SAS, South Asian. d) Proposed therapeutic design framework.

FIG. 13A-E : Left, fraction of PAMs altered by variants in the ExAC dataset; center, distribution of PAM-altering variant frequencies; right, fraction of homozygous variants by frequency. Data shown for AsCpf1 (a), SpCas9-VQR (b), SpCas9 (c), SaCas9 (d), and SpCas9-VRER (e).

FIG. 14A-D : Top, distribution of target variation for therapeutically relevant genes. Targets with frequencies of variation less than 0.01% (red line) are considered platinum. Bottom, fraction of all targets in these genes containing variation. Data shown for AsCpf1 (a), SpCas9-VWR (b), SpCas9-WT (c), SaCas9-WT (d).

FIG. 15 : Separation of 1000 Genomes individuals into super populations based on patient specific off-target profiles for targets spanning 12 therapeutically relevant genes. Principle components 1-5 shown. AFR, African; AMR, Ad mixed American; EAS, East Asian; EUR, European; SAS, South Asian.

FIG. 16 : Separation of 1000 Genomes individuals into populations based on patient specific off-target profiles for targets spanning 12 therapeutically relevant genes. Principle components 1-5 shown. CHB, Han Chinese in Beijing, China; JPT, Japanese in Tokyo, Japan; CHS, Southern Han Chinese; CDX, Chinese Dai in Xishuangbanna, China; KHV, Kinh in Ho Chi Minh City, Vietnam; CEU, Utah Residents (CEPH) with Northern and Western Ancestry; TSI, Toscani in Italia; FIN, Finnish in Finland; GBR, British in England and Scotland; IBS, Iberian Population in Spain; YRI, Yoruba in Ibadan, Nigeria; LWK, Luhya in Webuye, Kenya; GWD, Gambian in Western Divisions in the Gambia; MSL, Mende in Sierra Leone; ESN, Esan in Nigeria; ASW, Americans of African Ancestry in SW USA; ACB, African Caribbeans in Barbados; MXL, Mexican Ancestry from Los Angeles USA; PUR, Puerto Ricans from Puerto Rico; CLM, Colombians from Medellin, Colombia; PEL, Peruvians from Lima, Peru; GIH, Gujarati Indian from Houston, Tex.; PJL, Punjabi from Lahore, Pakistan; BEB, Bengali from Bangladesh; STU, Sri Lankan Tamil from the UK; ITU, Indian Telugu from the UK.

FIG. 17 : Separation of 1000 Genomes individuals by sex based on patient specific off-target profiles for targets spanning 12 therapeutically relevant genes. Principle components 1 -5 shown.

FIG. 18A-10C . Validation of PAM screen with wt AsCpf1. A. Colony growth in cam/amp media for clones containing the indicated PAM sequences. B. Bar graph showing sensitivity of wild-type AsCpf1 to substitutions mutations in the PAM. C. Screen readout, highlighting depleted hits. Each dot represents a distinct Cpf1 wildtype (WT) or mutant codon. The dashed line indicates 15-fold depletion. Red=stop codon; blue=WT codon.

FIG. 19A-19E shows Cpf1 target nuclease activity of AsCpf1 and LbCpf1 with truncated guides. FIG. 19A provides a key as to guide length depicted in panels B-D. FIG. 19B depicts activity of AsCpf1 with truncated guides targeting DNMT1-3. FIG. 19C depicts activity of AsCpf1 with truncated guides targeting DNMT1-4. FIG. 19D depicts activity of LbCpf1 with truncated guides targeting DNMT1-3. FIG. 19E depicts activity of AsCpf1 with truncated guides targeting DNMT1-4.

FIG. 20A-20E shows Cpf1 target nuclease activity of AsCpf1 and LbCpf1 with partially binding guides. All guides were 24nt in length, matching the target over a range from 24nt to 14nt. FIG. 20A provides a key as to partially binding guides depicted in panels B-D. FIG. 20B depicts activity of AsCpf1 with partially matching guides targeting DNMT1-3. FIG. 20C depicts activity of AsCpf1 with partially matching guides targeting DNMT1-4. FIG. 20D depicts activity of LbCpf1 with partially matching guides targeting DNMT1-3. FIG. 20E depicts activity of AsCpf1 with partially matching guides targeting DNMT1-4.

FIG. 21 . In vitro cleavage assay. AsCpf1 PAM mutant S542R/K607R have altered PAM specificities in vitro. A. PAM preference of S542R/K607R (RR) and A542R/K548V/N552R (RVR) variants compared to wild type. Normalized cleavage rates are represented for all 4-base PAM motifs for wild-type, S542R/K607R, and S542R/K548V/N552R variants; B. Targeting range of Cpf1 variants in the human genome, including WT (dark blue), S542R/K607R (yellow), and S542R/K548V/N552R (light yellow). The percentages indicate the proportion of all non-repetitive guide sequences (both top and bottom strands) represented by the corresponding PAM; C. Distance between nearest target sites in non-repetitive regions of the human genome for TTTV PAMs (dark blue) and all PAMs cleavable by any of the variants (yellow).

FIG. 22 : Validation of AsCpf1 PAM mutants in HEK293 cells. % indel as determined for the indicated Cpf1 mutants and the indicated PAM sequence for indicated target genes. Numbers following the indicated PAM site represent different target sequences (e.g. TGTG-48) and different transfections for a given target sequence (e.g. TGTG-48.2). Co-transfection of plasmid expressing AsCpf1 (WT or mutant) and plasmid expressing AsCpf1 DR+spacer. Targeted deep sequencing of targeted genomic locus 3 days post-transfection.

FIG. 23A-23D . A. Activity of the S542R/K548V/N552R variant at TATV target sites; B. Activity of the S542R/K607 variant at TYCV sites; C. Activity of the S542R/K607R variant at TYCV and CCCC target sites and activity of the S542R/K548V variant at TTTV target sites; D. Activity of the S542R/K607R variant at VYCV sites. All indel percentages were measured in HEK293 cells.

FIG. 24 Validation of AsCpf1 PAM mutant S542R/K607R in HEK293 cells. % indel as determined for the Cpf1 mutant and the indicated PAM sequence for 63 different target sites of various target genes. Co-transfection of plasmid expressing AsCpf1 (WT or mutant) and plasmid expressing AsCpf1 DR+spacer. Targeted deep sequencing of targeted genomic locus 3 days post-transfection.

FIG. 25 . Protein alignment of AsCpf1 (Acidaminococcus sp. BV3L6) and LbCpf1 (Lachnospiraceae bacterium ND2006).

FIG. 26 . Exemplary expression plasmids encoding mutant Cpf1 according to an embodiment of the invention. (A) pY036 encoding AsCpf1 mutant S542R/K607R. (B) pcDNA encoding AsCpf1 mutant S542R/K607R. Functional features are indicated on the respective maps and sequences.

FIG. 27A-27D . DNA targeting specificity of Cpf1 PAM variants. A. DNA double-strand Breaks Labeling In Situ and Sequencing (BLISS) for 4 target sites (VEGFA, GRIN2B, EMX1, and DNMT1) in HEK293 cells. The log 10 double-strand break (DSB) scores for BLISS are indicated by the purple heat map, and the relative PAM cleavage rates from the in vitro cleavage assay are indicated by the blue heat map. Mismatches in the last three bases of the guide are not highlighted as they do not impact cleavage efficiency. B. Evaluation of an additional target site with known TTTV off-target sites, demonstrating the contribution of PAM preference to off-target activity. C. Addition of a K949A mutation reduces off-target DNA cleavage. D. Combining K949A with the S542R/K548V/N552R and S542R/K607R PAM variants retains high levels of on-target activity for their preferred PAMs.

FIG. 28 : Is a diagram depicting example parameters to be selected and optimized in accordance with certain example embodiments.

FIG. 29 shows illustrations of AAV-CRISPR protein of the invention, wherein Cas9 protein is fused or tethered to VP3, for example at the N-terminus of VP3. Cas9 is attached to some, but not all VP3 subunits to avoid steric blocking of cell entry sites on AAV surface. In the AAV9.Cas9 vector, a Cas9 protein fused or tethered to the C-term of VP1, VP2 or VP3 is depicted.

FIG. 30A-30B shows a Western blot confirming expression of Cas9-VP3 fusion proteins in cells transfected with plasmids encoding for Cas9 and Cas9-VP3 fusions (AAVCas9:wt 1:6). (A) Left panel: SYPRO Ruby protein staining of fractions from AAVCas9:wt 1:6. Right panel: Anti-SpCas9 blotting of fractions from AAVCas9:wt 1:6. (B) Left panel: SYPRO Ruby protein staining of fractions from wtAAV9. Right panel: Anti-SpCas9 blotting of fractions from wtAAV9.

FIG. 31 illustrates exterior loops and interior sites in AAV9 VP3 for protein insertion.

FIG. 32 depicts electron micrography of wtAAV. Dark particle centers indication empty particles.

FIG. 33 depicts electron micrography of AAV.Cas9 virus particles comprising 50wtAAV:10AAVCas9.

FIG. 34 depicts electron micrography of AAV.Cas9 virus particles comprising 30wtAAV:30AAVCas9.

FIG. 35A-35B depicts sortase-mediated protein linkage. (A) schematic of proteins anchored to a cell wall via sortase in Gram-positive bacteria is shown (see, Guimares, et al., Nat. Prot. 2013). (B) linkage of Cas9 to AAV by TEV-sortase method. CRISPR protein modified at its C terminus with the LPXTG sortase-recognition motif followed by a handle for purification (often His6) is incubated with sortase A. Sortase cleaves the threonine-glycine bond and forms an acyl intermediate with threonine. Addition of TEV-cleaved AAV (“probe”) comprising N-terminal glycine residues ligates the AAV to the C terminus of the CRISPR protein (see, Guimares, et al., Nat. Prot. 2013).

FIG. 36 depicts linkage of Cas9 to AAV by split intein reconstitution.

FIG. 37A-37B shows interior packaging of proteins:

FIG. 38 shows Interior SunTag-GFP. Western blots detect VP3 (top left) and GFP (bottom left) for native VP3 and VP3-GFP fusion. Electron micrographs show GFP-filled capsid (103).

FIG. 39 depicts Vesicular stomatitis virus (VSV) and Rabies virus (RV) sources of packaging vesicles.

FIG. 40 shows a schematic for transduction of cells with lentiviral vectors packaged in vesicular stomatitis virus-G (VSVG) vesicles. (Cronin et al., Curr Gene Ther. 5(4):387-398 (2005)).

FIG. 41 depicts infection of TLR19 cells with VSVG and RVG vesicles harboring Cas9 and sgRNA inducing frameshift mutations to allow mCherry expression. Cas9 RNP vesicles were synthesized by contransfection of VSVG (or RVG) with eSpCas9(1.1) and plasmid GFPg2.

FIG. 42 provides an alignment of AsCpf1 and FnCpf1, identifying Rad50 binding domains and the arginines and lysines within.

FIG. 43 provides a crystal structure of two similar domains as those found in Cpf1.

FIG. 44 provides a crystal structure of Aspf1 with regions that correspond to DNA binding regions annotated.

The figures herein are for illustrative purposes only and are not necessarily drawn to scale.

General Definitions

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Definitions of common terms and techniques in molecular biology may be found in Molecular Cloning: A Laboratory Manual, 2 nd edition (1989) (Sambrook, Fritsch, and Maniatis); Molecular Cloning: A Laboratory Manual, 4 th edition (2012) (Green and Sambrook); Current Protocols in Molecular Biology (1987) (F. M. Ausubel et al. eds.); the series Methods in Enzymology (Academic Press, Inc.): PCR 2: A Practical Approach (1995) (M. J. MacPherson, B. D. Hames, and G. R. Taylor eds.): Antibodies, A Laboratory Manual (1988) (Harlow and Lane, eds.): Antibodies A Laboratory Manual, 2nd edition 2013 (E. A. Greenfield ed.); Animal Cell Culture (1987) (R. I. Freshney, ed.); Benjamin Lewin, Genes IX, published by Jones and Bartlet, 2008 (ISBN 0763752223); Kendrew et al. (eds.), The Encyclopedia of Molecular Biology, published by Blackwell Science Ltd., 1994 (ISBN 0632021829); Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by VCH Publishers, Inc., 1995 (ISBN 9780471185710); Singleton et al., Dictionary of Microbiology and Molecular Biology 2nd ed., J. Wiley & Sons (New York, N.Y. 1994), March, Advanced Organic Chemistry Reactions, Mechanisms and Structure 4th ed., John Wiley & Sons (New York, N.Y. 1992); and Marten H. Hofker and Jan van Deursen, Transgenic Mouse Methods and Protocols, 2 nd edition (2011).

As used herein, the singular forms “a”, “an”, and “the” include both singular and plural referents unless the context clearly dictates otherwise.

The term “optional” or “optionally” means that the subsequent described event, circumstance or substituent may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

The terms “about” or “approximately” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specified value, such as variations of +/−10% or less, +/−5% or less, +/−1% or less, and +/−0.1% or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier “about” or “approximately” refers is itself also specifically, and preferably, disclosed.

Reference throughout this specification to “one embodiment”, “an embodiment,” “an example embodiment,” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “an example embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

It will be appreciated that the terms Cas enzyme, CRISPR enzyme, CRISPR protein, Cas protein and CRISPR-Cas are generally used interchangeably and at all points of reference herein refer by analogy to novel CRISPR effector proteins further described in this application, unless otherwise apparent, such as by specific reference to Cas9 or Cpf1. The CRISPR effector proteins described herein are preferably Cpf1 effector proteins.

All publications, published patent documents, and patent applications cited herein are hereby incorporated by reference to the same extent as though each individual publication, published patent document, or patent application was specifically and individually indicated as being incorporated by reference.

Overview

In one aspect, embodiments disclosed herein are directed to engineered CRISPR-Cas effector proteins that comprise at least one modification compared to an unmodified CRISPR-Cas effector protein that enhances binding of the CRISPR complex to the binding site and/or alters editing preference as compared to wild type. In certain example embodiments, the CRISPR-Cas effector protein is a Type V effector protein. In certain other example embodiments, the Type V effector protein is Cpf1. Example Cpf1 proteins suitable for use in the embodiments disclosed herein are discussed in further detail below.

In another aspect, embodiments disclosed herein are directed to viral vectors for delivery of CRISPR-Cas effector proteins, including Cpf1. In certain example embodiments, the vectors are designed so as to allow packaging of the CRISPR-Cas effector protein within a single vector. There is also an increased interest in the design of compact promoters for packing and thus expressing larger transgenes for targeted delivery and tissue-specificity. Thus, in another aspect certain embodiments disclosed herein are directed to delivery vectors, constructs, and methods of delivering larger genes for systemic delivery.

In another aspect, the present invention relates to methods for developing or designing CRISPR-Cas systems. In an aspect, the present invention relates to methods for developing or designing optimized CRISPR-Cas systems a wide range of applications including, but not limited to, therapeutic development, bioproduction, and plant and agricultural applications. In certain based therapy or therapeutics. The present invention in particular relates to methods for improving CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. Key characteristics of successful CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics involve high specificity, high efficacy, and high safety. High specificity and high safety can be achieved among others by reduction of off-target effects. Improved specificity and efficacy likewise may be used to improve applications in plants and bioproduction.

Accordingly, in an aspect, the present invention relates to methods for increasing specificity of CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. In a further aspect, the invention relates to methods for increasing efficacy of CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. In a further aspect, the invention relates to methods for increasing safety of CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. In a further aspect, the present invention relates to methods for increasing specificity, efficacy, and/or safety, preferably all, of CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics.

In certain embodiments, the CRISPR-Cas system comprises a CRISPR effector as defined herein elsewhere.

The methods of the present invention in particular involve optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, as described herein further elsewhere. Optimization of the CRISPR-Cas system in the methods as described herein may depend on the target(s), such as the therapeutic target or therapeutic targets, the mode or type of CRISPR-Cas system modulation, such as CRISPR-Cas system based therapeutic target(s) modulation, modification, or manipulation, as well as the delivery of the CRISPR-Cas system components. One or more targets may be selected, depending on the genotypic and/or phenotypic outcome. For instance, one or more therapeutic targets may be selected, depending on (genetic) disease etiology or the desired therapeutic outcome. The (therapeutic) target(s) may be a single gene, locus, or other genomic site, or may be multiple genes, loci or other genomic sites. As is known in the art, a single gene, locus, or other genomic site may be targeted more than once, such as by use of multiple gRNAs.

CRISPR-Cas system activity, such as CRISPR-Cas system design may involve target disruption, such as target mutation, such as leading to gene knockout. CRISPR-Cas system activity, such as CRISPR-Cas system design may involve replacement of particular target sites, such as leading to target correction. CRISPR-Cas system design may involve removal of particular target sites, such as leading to target deletion. CRISPR-Cas system activity may involve modulation of target site functionality, such as target site activity or accessibility, leading for instance to (transcriptional and/or epigenetic) gene or genomic region activation or gene or genomic region silencing. The skilled person will understand that modulation of target site functionality may involve CRISPR effector mutation (such as for instance generation of a catalytically inactive CRISPR effector) and/or functionalization (such as for instance fusion of the CRISPR effector with a heterologous functional domain, such as a transcriptional activator or repressor), as described herein elsewhere.

Engineered CRISPR-Cas Systems

In general, CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), also known as SPIDRs (SPacer Interspersed Direct Repeats), constitute a family of DNA loci that are usually specific to a particular bacterial species. The CRISPR locus comprises a distinct class of interspersed short sequence repeats (SSRs) that were recognized in E. coli (Ishino et al., J. Bacteriol., 169:5429-5433 [1987]; and Nakata et al., J. Bacteriol., 171:3553-3556 [1989]), and associated genes. Similar interspersed SSRs have been identified in Haloferax mediterranei, Streptococcus pyogenes, Anabaena , and Mycobacterium tuberculosis (See, Groenen et al., Mol. Microbiol., 10:1057-1065 [1993]; Hoe et al., Emerg. Infect. Dis., 5:254-263 [1999]; Masepohl et al., Biochim. Biophys. Acta 1307:26-30 [1996]; and Mojica et al., Mol. Microbiol., 17:85-93 [1995]). The CRISPR loci typically differ from other SSRs by the structure of the repeats, which have been termed short regularly spaced repeats (SRSRs) (Janssen et al., OMICS J. Integ. Biol., 6:23-33 [2002]; and Mojica et al., Mol. Microbiol., 36:244-246 [2000]). In general, the repeats are short elements that occur in clusters that are regularly spaced by unique intervening sequences with a substantially constant length (Mojica et al., [2000], supra). Although the repeat sequences are highly conserved between strains, the number of interspersed repeats and the sequences of the spacer regions typically differ from strain to strain (van Embden et al., J. Bacteriol., 182:2393-2401 [2000]). CRISPR loci have been identified in more than 40 prokaryotes (See e.g., Jansen et al., Mol. Microbiol., 43:1565-1575 [2002]; and Mojica et al., [2005]) including, but not limited to Aeropyrum, Pyrobaculum, Sulfolobus, Archaeoglobus, Haloarcula, Methanobacterium, Methanococcus, Methanosarcina, Methanopyrus, Pyrococcus, Picrophilus, Thermoplasma, Corynebacterium, Mycobacterium, Streptomyces, Aquifex, Porphyromonas, Chlorobium, Thermus, Bacillus, Listeria, Staphylococcus, Clostridium, Thermoanaerobacter, Mycoplasma, Fusobacterium, Azoarcus, Chromobacterium, Neisseria, Nitrosomonas, Desulfovibrio, Geobacter, Myxococcus, Campylobacter, Wolinella, Acinetobacter, Erwinia, Escherichia, Legionella, Methylococcus, Pasteurella, Photobacterium, Salmonella, Xanthomonas, Yersinia, Treponema , and Thermotoga.

General Features of Cpf1 Effector Protein

The present invention encompasses the use of a Cpf1 effector protein, derived from a Cpf1 locus denoted as subtype V-A. Herein such effector proteins are also referred to as “Cpf1p”, e.g., a Cpf1 protein (and such effector protein or Cpf1 protein or protein derived from a Cpf1 locus is also called “CRISPR enzyme”). Presently, the subtype V-A loci encompasses cas1, cas2, a distinct gene denoted Cpf1 and a CRISPR array. Cpf1(CRISPR-associated protein Cpf1, subtype PREFRAN) is a large protein (about 1300 amino acids) that contains a RuvC-like nuclease domain homologous to the corresponding domain of Cas9 along with a counterpart to the characteristic arginine-rich cluster of Cas9. However, Cpf1 lacks the HNH nuclease domain that is present in all Cas9 proteins, and the RuvC-like domain is contiguous in the Cpf1 sequence, in contrast to Cas9 where it contains long inserts including the HNH domain. Accordingly, in particular embodiments, the CRISPR-Cas enzyme comprises only a RuvC-like nuclease domain.

Methods for Identifying New CRISPR-Cas Loci

The Cpf1 gene is found in several diverse bacterial genomes, typically in the same locus with cas1, cas2, and cas4 genes and a CRISPR cassette (for example, FNFX1_1431-FNFX1_1428 of Francisella cf. novicida Fx1). Thus, the layout of this novel CRISPR-Cas system appears to be similar to that of type II-B. Furthermore, similar to Cas9, the Cpf1 protein contains a readily identifiable C-terminal region that is homologous to the transposon ORF-B and includes an active RuvC-like nuclease, an arginine-rich region, and a Zn finger (absent in Cas9). However, unlike Cas9, Cpf1 is also present in several genomes without a CRISPR-Cas context and its relatively high similarity with ORF-B suggests that it might be a transposon component. It was suggested that if this was a genuine CRISPR-Cas system and Cpf1 is a functional analog of Cas9 it would be a novel CRISPR-Cas type, namely type V (See Annotation and Classification of CRISPR-Cas Systems. Makarova K S, Koonin EV. Methods Mol Biol. 2015; 1311:47-75). However, as described herein, Cpf1 is denoted to be in subtype V-A to distinguish it from C2c1p which does not have an identical domain structure and is hence denoted to be in subtype V-B. The application describes methods for using CRISPR-Cas proteins in therapy. This is exemplified herein with Cpf1, whereby a number of Cpf1 orthologs or homologs have been identified. It will be apparent to the skilled person that further Cpf1 orthologs or homologs can be identified and that any of the functionalities described herein may be engineered into other Cpf1 orthologs, including chimeric enzymes comprising fragments from multiple orthologs.

For instance, computational methods of identifying novel CRISPR-Cas loci are described in EP3009511 or US2016208243 and may comprise the following steps: detecting all contigs encoding the Cas1 protein; identifying all predicted protein coding genes within 20 kB of the cas1 gene; comparing the identified genes with Cas protein-specific profiles and predicting CRISPR arrays; selecting unclassified candidate CRISPR-Cas loci containing proteins larger than 500 amino acids (>500 aa); analyzing selected candidates using methods such as PSI-BLAST and HHPred to screen for known protein domains, thereby identifying novel Class 2 CRISPR-Cas loci (see also Schmakov et al. 2015, Mol Cell. 60(3):385-97). In addition to the above mentioned steps, additional analysis of the candidates may be conducted by searching metagenomics databases for additional homologs. Additionally or alternatively, to expand the search to non-autonomous CRISPR-Cas systems, the same procedure can be performed with the CRISPR array used as the seed.

In one aspect the detecting all contigs encoding the Cas1 protein is performed by GenemarkS which a gene prediction program as further described in “GeneMarkS: a self-training method for prediction of gene starts in microbial genomes. Implications for finding sequence motifs in regulatory regions.” John Besemer, Alexandre Lomsadze and Mark Borodovsky, Nucleic Acids Research (2001) 29, pp 2607-2618, herein incorporated by reference.

In one aspect the identifying all predicted protein coding genes is carried out by comparing the identified genes with Cas protein-specific profiles and annotating them according to NCBI Conserved Domain Database (CDD) which is a protein annotation resource that consists of a collection of well-annotated multiple sequence alignment models for ancient domains and full-length proteins. These are available as position-specific score matrices (PSSMs) for fast identification of conserved domains in protein sequences via RPS-BLAST. CDD content includes NCBI-curated domains, which use 3D-structure information to explicitly define domain boundaries and provide insights into sequence/structure/function relationships, as well as domain models imported from a number of external source databases (Pfam, SMART, COG, PRK, TIGRFAM). In a further aspect, CRISPR arrays were predicted using a PILER-CR program which is a public domain software for finding CRISPR repeats as described in “PILER-CR: fast and accurate identification of CRISPR repeats”, Edgar, R. C., BMC Bioinformatics, January 20; 8:18(2007), herein incorporated by reference.

In a further aspect, the case by case analysis is performed using PSI-BLAST (Position-Specific Iterative Basic Local Alignment Search Tool). PSI-BLAST derives a position-specific scoring matrix (PSSM) or profile from the multiple sequence alignment of sequences detected above a given score threshold using protein-protein BLAST. This PSSM is used to further search the database for new matches, and is updated for subsequent iterations with these newly detected sequences. Thus, PSI-BLAST provides a means of detecting distant relationships between proteins.

In another aspect, the case by case analysis is performed using HHpred, a method for sequence database searching and structure prediction that is as easy to use as BLAST or PSI-BLAST and that is at the same time much more sensitive in finding remote homologs. In fact, HHpred's sensitivity is competitive with the most powerful servers for structure prediction currently available. HHpred is the first server that is based on the pairwise comparison of profile hidden Markov models (HMMs). Whereas most conventional sequence search methods search sequence databases such as UniProt or the NR, HHpred searches alignment databases, like Pfam or SMART. This greatly simplifies the list of hits to a number of sequence families instead of a clutter of single sequences. All major publicly available profile and alignment databases are available through HHpred. HHpred accepts a single query sequence or a multiple alignment as input. Within only a few minutes it returns the search results in an easy-to-read format similar to that of PSI-BLAST. Search options include local or global alignment and scoring secondary structure similarity. HHpred can produce pairwise query-template sequence alignments, merged query-template multiple alignments (e.g. for transitive searches), as well as 3D structural models calculated by the MODELLER software from HHpred alignments.

In certain example embodiments, methods for identifying novel CRISPR loci may include comparison to properties and elements of known CRISPR loci. Example methods are disclosed in U.S. Provisional Application No. 62/376,387 filed Aug. 17, 2016 and entitled “Methods for identifying Class 2 CRISPR-Cas systems,” U.S. Provisional Application No. 62/376,383 filed Aug. 17, 2016 and entitled “Methods for Identifying Novel Gene Editing Elements,” and Shmakov et al. “Diversity and evolution of class 2 CRISPR-Cas systems,” Nat Rev Microbiol. 2017 15(3):169-182. Finally, methods such as those disclosed above may also be adaptive to identify genomic structures comprising repeating motifs in general as opposed to specific known CRISPR objects such as Cas9 or Cpf1.

It should be further recognized that putative novel CRISPR-Cas loci may be further discovered and/or integrated, in particular for relevant nuclease activity, using the methods disclosed in the section below under the header “Methods for determining on/off target activity and selecting suitable sequences/guides.”

Orthologs of Cpf1

The terms “orthologue” (also referred to as “ortholog” herein) and “homologue” (also referred to as “homolog” herein) are well known in the art. By means of further guidance, a “homologue” of a protein as used herein is a protein of the same species which performs the same or a similar function as the protein it is a homologue of. Homologous proteins may but need not be structurally related, or are only partially structurally related. An “orthologue” of a protein as used herein is a protein of a different species which performs the same or a similar function as the protein it is an orthologue of Orthologous proteins may but need not be structurally related, or are only partially structurally related. Homologs and orthologs may be identified by homology modelling (see, e.g., Greer, Science vol. 228 (1985) 1055, and Blundell et al. Eur J Biochem vol 172 (1988), 513) or “structural BLAST” (Dey F, Cliff Zhang Q, Petrey D, Honig B. Toward a “structural BLAST”: using structural relationships to infer function. Protein Sci. 2013 April; 22(4):359-66. doi: 10.1002/pro.2225.). See also Shmakov et al. (2015) for application in the field of CRISPR-Cas loci. Homologous proteins may but need not be structurally related, or are only partially structurally related.

The Cpf1 gene is found in several diverse bacterial genomes, typically in the same locus with cas1, cas2, and cas4 genes and a CRISPR cassette (for example, FNFX1_1431-FNFX1_1428 of Francisella cf. novicida Fx1). Thus, the layout of this putative novel CRISPR-Cas system appears to be similar to that of type II-B. Furthermore, similar to Cas9, the Cpf1 protein contains a readily identifiable C-terminal region that is homologous to the transposon ORF-B and includes an active RuvC-like nuclease, an arginine-rich region, and a Zn finger (absent in Cas9). However, unlike Cas9, Cpf1 is also present in several genomes without a CRISPR-Cas context and its relatively high similarity with ORF-B suggests that it might be a transposon component. It was suggested that if this was a genuine CRISPR-Cas system and Cpf1 is a functional analog of Cas9 it would be a novel CRISPR-Cas type, namely type V (See Annotation and Classification of CRISPR-Cas Systems. Makarova K S, Koonin EV. Methods Mol Biol. 2015; 1311:47-75). However, as described herein, Cpf1 is denoted to be in subtype V-A to distinguish it from C2c1p which does not have an identical domain structure and is hence denoted to be in subtype V-B.

In particular embodiments, the effector protein is a Cpf1 effector protein from an organism from a genus comprising Streptococcus, Campylobacter, Nitratifractor, Staphylococcus, Parvibaculum, Roseburia, Neisseria, Gluconacetobacter, Azospirillum, Sphaerochaeta, Lactobacillus, Eubacterium, Corynebacter, Carnobacterium, Rhodobacter, Listeria, Paludibacter, Clostridium, Lachnospiraceae, Leptotrichia, Francisella, Legionella, Alicyclobacillus, Methanomethyophilus, Porphyromonas, Prevotella, Bacteroidetes, Helcococcus, Leptospira, Desulfovibrio, Desulfonatronum, Opitutaceae, Tuberibacillus, Bacillus, Brevibacillus, Methylobacterium or Acidaminococcus.

In further particular embodiments, the Cpf1 effector protein is from an organism selected from S. mutans, S. agalactiae, S. equisimilis, S. sanguinis, S. pneumonia; C. jejuni, C. coli; N. salsuginis, N. tergarcus; S. auricularis, S. carnosus; N. meningitides, N. gonorrhoeae; L. monocytogenes, L. ivanovii; C. botulinum, C. difficile, C. tetani, C. sordellii.

The effector protein may comprise a chimeric effector protein comprising a first fragment from a first effector protein (e.g., a Cpf1) ortholog and a second fragment from a second effector (e.g., a Cpf1) protein ortholog, and wherein the first and second effector protein orthologs are different. At least one of the first and second effector protein (e.g., a Cpf1) orthologs may comprise an effector protein (e.g., a Cpf1) from an organism comprising Streptococcus, Campylobacter, Nitratifractor, Staphylococcus, Parvibaculum, Roseburia, Neisseria, Gluconacetobacter, Azospirillum, Sphaerochaeta, Lactobacillus, Eubacterium, Corynebacter, Carnobacterium, Rhodobacter, Listeria, Paludibacter, Clostridium, Lachnospiraceae, Leptotrichia, Francisella, Legionella, Alicyclobacillus, Methanomethyophilus, Porphyromonas, Prevotella, Bacteroidetes, Helcococcus, Leptospira, Desulfovibrio, Desulfonatronum, Opitutaceae, Tuberibacillus, Bacillus, Brevibacillus, Methylobacterium or Acidaminococcus ; e.g., a chimeric effector protein comprising a first fragment and a second fragment wherein each of the first and second fragments is selected from a Cpf1 of an organism comprising Streptococcus, Campylobacter, Nitratifractor, Staphylococcus, Parvibaculum, Roseburia, Neisseria, Gluconacetobacter, Azospirillum, Sphaerochaeta, Lactobacillus, Eubacterium, Corynebacter, Carnobacterium, Rhodobacter, Listeria, Paludibacter, Clostridium, Lachnospiraceae, Leptotrichia, Francisella, Legionella, Alicyclobacillus, Methanomethyophilus, Porphyromonas, Prevotella, Bacteroidetes, Helcococcus, Leptospira, Desulfovibrio, Desulfonatronum, Opitutaceae, Tuberibacillus, Bacillus, Brevivacillus, Methylobacterium or Acidaminococcus wherein the first and second fragments are not from the same bacteria; for instance a chimeric effector protein comprising a first fragment and a second fragment wherein each of the first and second fragments is selected from a Cpf1 of S. mutans, S. agalactiae, S. equisimilis, S. sanguinis, S. pneumonia; C. jejuni, C. coli; N. salsuginis, N. tergarcus; S. auricularis, S. carnosus; N. meningitides, N. gonorrhoeae; L. monocytogenes, L. ivanovii; C. botulinum, C. difficile, C. tetani, C. sordellii; Francisella tularensis 1 , Prevotella albensis, Lachnospiraceae bacterium MC2017 1 , Butyrivibrio proteoclasticus, Peregrinibacteria bacterium GW2011_GWA2_33_10 , Parcubacteria bacterium GW2011_GWC2_44 _17 , Smithella sp. SCADC, Acidaminococcus sp. BV3L6 , Lachnospiraceae bacterium MA2020 , Candidatus Methanoplasma termitum, Eubacterium eligens, Moraxella bovoculi 237 , Leptospira inadai, Lachnospiraceae bacterium ND2006 , Porphyromonas crevioricanis 3 , Prevotella disiens and Porphyromonas macacae , wherein the first and second fragments are not from the same bacteria.

In a more preferred embodiment, the Cpf1p is derived from a bacterial species selected from Francisella tularensis 1 , Prevotella albensis, Lachnospiraceae bacterium MC2017 1 , Butyrivibrio proteoclasticus, Peregrinibacteria bacterium GW2011_GWA2_33_10 , Parcubacteria bacterium GW2011 GWC2_44_17 , Smithella sp. SCADC, Acidaminococcus sp. BV3L6 , Lachnospiraceae bacterium MA2020 , Candidatus Methanoplasma termitum, Eubacterium eligens, Moraxella bovoculi 237 , Leptospira inadai, Lachnospiraceae bacterium ND2006 , Porphyromonas crevioricanis 3 , Prevotella disiens and Porphyromonas macacae . In certain embodiments, the Cpf1p is derived from a bacterial species selected from Acidaminococcus sp. BV3L6 , Lachnospiraceae bacterium MA2020. In certain embodiments, the effector protein is derived from a subspecies of Francisella tularensis 1, including but not limited to Francisella tularensis subsp. Novicida.

In particular embodiments, the homologue or orthologue of Cpf1 as referred to herein has a sequence homology or identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with Cpf1. In further embodiments, the homologue or orthologue of Cpf1 as referred to herein has a sequence identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with the wild type Cpf1. Where the Cpf1 has one or more mutations (mutated), the homologue or orthologue of said Cpf1 as referred to herein has a sequence identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with the mutated Cpf1.

In an embodiment, the Cpf1 protein may be an ortholog of an organism of a genus which includes, but is not limited to Acidaminococcus sp, Lachnospiraceae bacterium or Moraxella bovoculi ; in particular embodiments, the type V Cas protein may be an ortholog of an organism of a species which includes, but is not limited to Acidaminococcus sp. BV3L6 ; Lachnospiraceae bacterium ND2006 (LbCpf1) or Moraxella bovoculi 237.In particular embodiments, the homologue or orthologue of Cpf1 as referred to herein has a sequence homology or identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with one or more of the Cpf1 sequences disclosed herein. In further embodiments, the homologue or orthologue of Cpf as referred to herein has a sequence identity of at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with the wild type FnCpf1, AsCpf1 or LbCpf1.

In particular embodiments, the Cpf1 protein of the invention has a sequence homology or identity of at least 60%, more particularly at least 70, such as at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with FnCpf1, AsCpf1 or LbCpf1. In further embodiments, the Cpf1 protein as referred to herein has a sequence identity of at least 60%, such as at least 70%, more particularly at least 80%, more preferably at least 85%, even more preferably at least 90%, such as for instance at least 95% with the wild type AsCpf1 or LbCpf1. In particular embodiments, the Cpf1 protein of the present invention has less than 60% sequence identity with FnCpf1. The skilled person will understand that this includes truncated forms of the Cpf1 protein whereby the sequence identity is determined over the length of the truncated form.

In an embodiment of the invention, the effector protein comprises at least one HEPN domain, including but not limited to HEPN domains described herein, HEPN domains known in the art, and domains recognized to be HEPN domains by comparison to consensus sequences and motifs.

Determination of PAM

Determination of PAM can be ensured as follows This experiment closely parallels similar work in E. coli for the heterologous expression of StCas9 (Sapranauskas, R. et al. Nucleic Acids Res 39, 9275-9282 (2011)). Applicants introduce a plasmid containing both a PAM and a resistance gene into the heterologous E. coli , and then plate on the corresponding antibiotic. If there is DNA cleavage of the plasmid, Applicants observe no viable colonies.

In further detail, the assay is as follows for a DNA target. Two E. coli strains are used in this assay. One carries a plasmid that encodes the endogenous effector protein locus from the bacterial strain. The other strain carries an empty plasmid (e.g. pACYC184, control strain). All possible 7 or 8 bp PAM sequences are presented on an antibiotic resistance plasmid (pUC19 with ampicillin resistance gene). The PAM is located next to the sequence of proto-spacer 1 (the DNA target to the first spacer in the endogenous effector protein locus). Two PAM libraries were cloned. One has a 8 random bp 5′ of the proto-spacer (e.g. total of 65536 different PAM sequences=complexity). The other library has 7 random bp 3′ of the proto-spacer (e.g. total complexity is 16384 different PAMs). Both libraries were cloned to have in average 500 plasmids per possible PAM. Test strain and control strain were transformed with 5′PAM and 3′PAM library in separate transformations and transformed cells were plated separately on ampicillin plates. Recognition and subsequent cutting/interference with the plasmid renders a cell vulnerable to ampicillin and prevents growth. Approximately 12h after transformation, all colonies formed by the test and control strains where harvested and plasmid DNA was isolated. Plasmid DNA was used as template for PCR amplification and subsequent deep sequencing. Representation of all PAMs in the untransfomed libraries showed the expected representation of PAMs in transformed cells. Representation of all PAMs found in control strains showed the actual representation. Representation of all PAMs in test strain showed which PAMs are not recognized by the enzyme and comparison to the control strain allows extracting the sequence of the depleted PAM.

For the Cpf1 orthologues identified to date, the following PAMs have been identified: the Acidaminococcus sp. BV3L6 Cpf1 (AsCpf1) and Lachnospiraceae bacterium ND2006 Cpf1 (LbCpf1) can cleave target sites preceded by a TTTV PAM, FnCpf1p, can cleave sites preceded by TTN, where N is A/C/G or T.

Codon Optimized Nucleic Acid Sequences

Where the effector protein is to be administered as a nucleic acid, the application envisages the use of codon-optimized Cpf1 sequences. An example of a codon optimized sequence, is in this instance a sequence optimized for expression in a eukaryote, e.g., humans (i.e. being optimized for expression in humans), or for another eukaryote, animal or mammal as herein discussed; see, e.g., SaCas9 human codon optimized sequence in WO 2014/093622 (PCT/US2013/074667) as an example of a codon optimized sequence (from knowledge in the art and this disclosure, codon optimizing coding nucleic acid molecule(s), especially as to effector protein (e.g., Cpf1) is within the ambit of the skilled artisan). Whilst this is preferred, it will be appreciated that other examples are possible and codon optimization for a host species other than human, or for codon optimization for specific organs is known. In some embodiments, an enzyme coding sequence encoding a DNA/RNA-targeting Cas protein is codon optimized for expression in particular cells, such as eukaryotic cells. The eukaryotic cells may be those of or derived from a particular organism, such as a plant or a mammal, including but not limited to human, or non-human eukaryote or animal or mammal as herein discussed, e.g., mouse, rat, rabbit, dog, livestock, or non-human mammal or primate. In some embodiments, processes for modifying the germ line genetic identity of human beings and/or processes for modifying the genetic identity of animals which are likely to cause them suffering without any substantial medical benefit to man or animal, and also animals resulting from such processes, may be excluded. In general, codon optimization refers to a process of modifying a nucleic acid sequence for enhanced expression in the host cells of interest by replacing at least one codon (e.g., about or more than about 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, or more codons) of the native sequence with codons that are more frequently or most frequently used in the genes of that host cell while maintaining the native amino acid sequence. Various species exhibit particular bias for certain codons of a particular amino acid. Codon bias (differences in codon usage between organisms) often correlates with the efficiency of translation of messenger RNA (mRNA), which is in turn believed to be dependent on, among other things, the properties of the codons being translated and the availability of particular transfer RNA (tRNA) molecules. The predominance of selected tRNAs in a cell is generally a reflection of the codons used most frequently in peptide synthesis. Accordingly, genes can be tailored for optimal gene expression in a given organism based on codon optimization. Codon usage tables are readily available, for example, at the “Codon Usage Database” available at www.kazuka.or.jp/codon and these tables can be adapted in a number of ways. See Nakamura, Y., et al. “Codon usage tabulated from the international DNA sequence databases: status for the year 2000” Nucl. Acids Res. 28:292 (2000). Computer algorithms for codon optimizing a particular sequence for expression in a particular host cell are also available, such as Gene Forge (Aptagen; Jacobus, Pa.), are also available. In some embodiments, one or more codons (e.g., 1, 2, 3, 4, 5, 10, 15, 20, 25, 50, or more, or all codons) in a sequence encoding a DNA/RNA-targeting Cas protein corresponds to the most frequently used codon for a particular amino acid. As to codon usage in yeast, reference is made to the online Yeast Genome database available at www.yeastgenome.org/community/codon_usage.shtml, or Codon selection in yeast, Bennetzen and Hall, J Biol Chem. 1982 Mar. 25; 257(6):3026-31. As to codon usage in plants including algae, reference is made to Codon usage in higher plants, green algae, and cyanobacteria, Campbell and Gown, Plant Physiol. 1990 January; 92(1): 1-11.; as well as Codon usage in plant genes, Murray et al, Nucleic Acids Res. 1989 Jan. 25; 17(2):477-98; or Selection on the codon bias of chloroplast and cyanelle genes in different plant and algal lineages, Morton B R, J Mol Evol. 1998 April; 46(4):449-59.

Modified Cpf1 Enzymes

In particular embodiments, it is of interest to make us of an engineered Cpf1 protein as defined herein, such as Cpf1, wherein the protein complexes with a nucleic acid molecule comprising RNA to form a CRISPR complex, wherein when in the CRISPR complex, the nucleic acid molecule targets one or more target polynucleotide loci, the protein comprises at least one modification compared to unmodified Cpf1 protein, and wherein the CRISPR complex comprising the modified protein has altered activity as compared to the complex comprising the unmodified Cpf1 protein. It is to be understood that when referring herein to CRISPR “protein”, the Cpf1 protein preferably is a modified CRISPR enzyme (e.g. having increased or decreased (or no) enzymatic activity, such as without limitation including Cpf1. The term “CRISPR protein” may be used interchangeably with “CRISPR enzyme”, irrespective of whether the CRISPR protein has altered, such as increased or decreased (or no) enzymatic activity, compared to the wild type CRISPR protein.

Computational analysis of the primary structure of Cpf1 nucleases reveals three distinct regions. First a C-terminal RuvC like domain, which is the only functional characterized domain. Second a N-terminal alpha-helical region and third a mixed alpha and beta region, located between the RuvC like domain and the alpha-helical region.

Several small stretches of unstructured regions are predicted within the Cpf1 primary structure. Unstructured regions, which are exposed to the solvent and not conserved within different Cpf1 orthologs, are preferred sides for splits and insertions of small protein sequences ( FIGS. 10 and 11 ). In addition, these sides can be used to generate chimeric proteins between Cpf1 orthologs.

In certain example embodiments, a modified Cpf1 protein comprises at least one modification that alters editing preference as compared to wild type. In certain example embodiments, the editing preference is for a specific insert or deletion within the target region. In certain example embodiments, the at least one modification increases formation of one or more specific indels. In certain example embodiments, the at least one modification is in a C-terminal RuvC like domain, the N-terminal alpha-helical region, the mixed alpha and beta region, or a combination thereof. In certain example embodiments the altered editing preference is indel formation. In certain example embodiments, the at least one modification increases formation of one or more specific insertions.

In certain example embodiments, the at least one modification increases formation of one or more specific insertions. In certain example embodiments, the at least one modification results in an insertion of an A adjacent to an A, T, G, or C in the target region. In another example embodiment, the at least one modification results in insertion of a T adjacent to an A, T, G, or C in the target region. In another example embodiment, the at least one modification results in insertion of a G adjacent to an A, T, G, or C in the target region. In another example embodiment, the at least one modification results in insertion of a C adjacent to an A, T, C, or G in the target region. The insertion may be 5′ or 3′ to the adjacent nucleotide. In one example embodiment, the one or more modification direct insertion of a T adjacent to an existing T. In certain example embodiments, the existing T corresponds to the 4th position in the binding region of a guide sequence. In certain example embodiments, the one or more modifications result in an enzyme which ensures more precise one-base insertions or deletions, such as those described above. More particularly, the one or more modifications may reduce the formations of other types of indels by the enzyme. The ability to generate one-base insertions or deletions can be of interest in a number of applications, such as correction of genetic mutants in diseases caused by small deletions, more particularly where HDR is not possible. For example correction of the F508del mutation in CFTR via delivery of three sRNA directing insertion of three T's, which is the most common genotype of cystic fibrosis, or correction of Alia Jafar's single nucleotide deletion in CDKL5 in the brain. As the editing method only requires NHEJ, the editing would be possible in post-mitotic cells such as the brain. The ability to generate one base pair insertions/deletions may also be useful in genome-wide CRISPR-Cas negative selection screens. In certain example embodiments, the at least one modification, is a mutation. In certain other example embodiment, the one or more modification may be combined with one or more additional modifications or mutations described below including modifications to increase binding specificity and/or decrease off-target effects.

In certain example embodiments, the engineered CRISPR-Cas effector comprising at least one modification that alters editing preference as compared to wild type may further comprise one or more additional modifications that alters the binding property as to the nucleic acid molecule comprising RNA or the target polypeptide loci, altering binding kinetics as to the nucleic acid molecule or target molecule or target polynucleotide or alters binding specificity as to the nucleic acid molecule. Example of such modifications are summarized in the following paragraph. Based on the above information, mutants can be generated which lead to inactivation of the enzyme or which modify the double strand nuclease to nickase activity. In alternative embodiments, this information is used to develop enzymes with reduced off-target effects (described elsewhere herein).

In certain of the above-described Cpf1 enzymes, the enzyme is modified by mutation of one or more residues including but not limited to positions D917, E1006, E1028, D1227, D1255A, N1257, according to FnCpf1 protein or any corresponding ortholog. In an aspect the invention provides a herein-discussed composition wherein the Cpf1 enzyme is an inactivated enzyme which comprises one or more mutations selected from the group consisting of D917A, E1006A, E1028A, D1227A, D1255A, N1257A, D917A, E1006A, E1028A, D1227A, D1255A and N1257A according to FnCpf1 protein or corresponding positions in a Cpf1 ortholog. In an aspect the invention provides a herein-discussed composition, wherein the CRISPR enzyme comprises D917, or E1006 and D917, or D917 and D1255, according to FnCpf1 protein or a corresponding position in a Cpf1 ortholog.

In certain of the above-described Cpf1 enzymes, the enzyme is modified by mutation of one or more residues (in the RuvC domain) including but not limited to positions R909, R912, R930, R947, K949, R951, R955, K965, K968, K1000, K1002, R1003, K1009, K1017, K1022, K1029, K1035, K1054, K1072, K1086, R1094, K1095, K1109, K1118, K1142, K1150, K1158, K1159, R1220, R1226, R1242, and/or R1252 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6).

In certain of the above-described non-naturally-occurring CRISPR enzymes, the enzyme is modified by mutation of one or more residues (in the RAD50) domain including but not limited positions K324, K335, K337, R331, K369, K370, R386, R392, R393, K400, K404, K406, K408, K414, K429, K436, K438, K459, K460, K464, R670, K675, R681, K686, K689, R699, K705, R725, K729, K739, K748, and/or K752 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6).

In certain of the Cpf1 enzymes, the enzyme is modified by mutation of one or more residues including but not limited positions R912, T923, R947, K949, R951, R955, K965, K968, K1000, R1003, K1009, K1017, K1022, K1029, K1072, K1086, F1103, R1226, and/or R1252 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6).

In certain embodiments, the Cpf1 enzyme is modified by mutation of one or more residues including but not limited positions R833, R836, K847, K879, K881, R883, R887, K897, K900, K932, R935, K940, K948, K953, K960, K984, K1003, K1017, R1033, R1138, R1165, and/or R1252 with reference to amino acid position numbering of LbCpf1 ( Lachnospiraceae bacterium ND2006).

In certain embodiments, the Cpf1 enzyme is modified by mutation of one or more residues including but not limited positions K15, R18, K26, Q34, R43, K48, K51, R56, R84, K85, K87, N93, R103, N104, T118, K123, K134, R176, K177, R192, K200, K226, K273, K275, T291, R301, K307, K369, S404, V409, K414, K436, K438, K468, D482, K516, R518, K524, K530, K532, K548, K559, K570, R574, K592, D596, K603, K607, K613, C647, R681, K686, H720, K739, K748, K757, T766, K780, R790, P791, K796, K809, K815, T816, K860, R862, R863, K868, K897, R909, R912, T923, R947, K949, R951, R955, K965, K968, K1000, R1003, K1009, K1017, K1022, K1029, A1053, K1072, K1086, F1103, S1209, R1226, R1252, K1273, K1282, and/or K1288 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6).

In certain embodiments, the enzyme is modified by mutation of one or more residues including but not limited positions K15, R18, K26, R34, R43, K48, K51, K56, K87, K88, D90, K96, K106, K107, K120, Q125, K143, R186, K187, R202, K210, K235, K296, K298, K314, K320, K326, K397, K444, K449, E454, A483, E491, K527, K541, K581, R583, K589, K595, K597, K613, K624, K635, K639, K656, K660, K667, K671, K677, K719, K725, K730, K763, K782, K791, R800, K809, K823, R833, K834, K839, K852, K858, K859, K869, K871, R872, K877, K905, R918, R921, K932, 1960, K962, R964, R968, K978, K981, K1013, R1016, K1021, K1029, K1034, K1041, K1065, K1084, and/or K1098 with reference to amino acid position numbering of FnCpf1 ( Francisella novicida U112).

In certain embodiments, the enzyme is modified by mutation of one or more residues including but not limited positions K15, R18, K26, K34, R43, K48, K51, R56, K83, K84, R86, K92, R102, K103, K116, K121, R158, E159, R174, R182, K206, K251, K253, K269, K271, K278, P342, K380, R385, K390, K415, K421, K457, K471, A506, R508, K514, K520, K522, K538, Y548, K560, K564, K580, K584, K591, K595, K601, K634, K640, R645, K679, K689, K707, T716, K725, R737, R747, R748, K753, K768, K774, K775, K785, K787, R788, Q793, K821, R833, R836, K847, K879, K881, R883, R887, K897, K900, K932, R935, K940, K948, K953, K960, K984, K1003, K1017, R1033, K1121, R1138, R1165, K1190, K1199, and/or K1208 with reference to amino acid position numbering of LbCpf1 ( Lachnospiraceae bacterium ND2006).

In certain embodiments, the enzyme is modified by mutation of one or more residues including but not limited positions K14, R17, R25, K33, M42, Q47, K50, D55, K85, N86, K88, K94, R104, K105, K118, K123, K131, R174, K175, R190, R198, 1221, K267, Q269, K285, K291, K297, K357, K403, K409, K414, K448, K460, K501, K515, K550, R552, K558, K564, K566, K582, K593, K604, K608, K623, K627, K633, K637, E643, K780, Y787, K792, K830, Q846, K858, K867, K876, K890, R900, K901, M906, K921, K927, K928, K937, K939, R940, K945, Q975, R987, R990, K1001, R1034, 11036, R1038, R1042, K1052, K1055, K1087, R1090, K1095, N1103, K1108, K1115, K1139, K1158, R1172, K1188, K1276, R1293, A1319, K1340, K1349, and/or K1356 with reference to amino acid position numbering of MbCpf1 ( Moraxella bovoculi 237).

Recently a method was described for the generation of Cas9 orthologs with enhanced specificity (Slaymaker et al. 2015). This strategy can be used to enhance the specificity of Cpf1 orthologs. The following modifications are presently considered to provide enhanced Cpf1 specificity.

Additional candidates are positive charged residues that are conserved between different orthologs.

Table 3 provides the positions of conserved Lysine and Arginine residues in an alignment of Cpf1 nuclease from Francisella novicida U112 (FnCpf1), Acidaminococcus sp. BV3L6 (AsCpf1), Lachnospiraceae bacterium ND2006 (LbCpf1) and Moraxella bovoculi 237 (MbCpf1). These can be used to generate Cpf1 mutants with enhanced specificity.

With a similar strategy used to improve Cas9 specificity, specificity of Cpf1 can be improved by mutating residues that stabilize the non-targeted DNA strand. This may be accomplished without a crystal structure by using linear structure alignments to predict 1) which domain of Cpf1 binds to which strand of DNA and 2) which residues within these domains contact DNA.

However, this approach may be limited due to poor conservation of Cpf1 with known proteins. Thus it may be desirable to probe the function of all likely DNA interacting amino acids (lysine, histidine and arginine).

Positively charged residues in the RuvC domain are more conserved throughout Cpf1s than those in the Rad50 domain indicating that RuvC residues are less evolutionarily flexible. This suggests that rigid control of nucleic acid binding is needed in this domain (relative to the Rad50 domain). Therefore, it is possible this domain cuts the targeted DNA strand because of the requirement for RNA:DNA duplex stabilization (precedent in Cas9). Furthermore, more arginines are present in the RuvC domain (5% of RuvC residues 904 to 1307 vs 3.8% in the proposed Rad50 domains) suggesting again that RuvC targets the DNA strand complexed with the guide RNA. Arginines are more involved in binding nucleic acid major and minor grooves (Rohs et al. Nature (2009): Vol 461: 1248-1254). Major/minor grooves would only be present in a duplex (such as DNA:RNA targeting duplex), further suggesting that RuvC cuts the “targeted strand”.

From these specific observations about AsCpf1 we can identify similar residues in Cpf1 from other species by sequence alignments. Example given in FIG. 42 of AsCpf1 and FnCpf1 aligned, identifying Rad50 binding domains and the Arginines and Lysines within.

FIG. 43 provides crystal structures of two similar domains as those found in Cpf1 (RuvC holiday junction resolvase and Rad50 DNA repair protein). Based on these structures, it can be deduced what the relevant domains look like in Cpf1, and infer which regions and residues may contact DNA. In each structure residues are highlighted that contact DNA. In the alignments in FIG. X4 the regions of AsCpf1 that correspond to these DNA binding regions are annotated. The list of residues in Table 4 are those found in the two binding domains.

Deactivated/Inactivated Cpf1 Protein

Where the Cpf1 protein has nuclease activity, the Cpf1 protein may be modified to have diminished nuclease activity e.g., nuclease inactivation of at least 70%, at least 80%, at least 90%, at least 95%, at least 97%, or 100% as compared with the wild type enzyme; or to put in another way, a Cpf1 enzyme having advantageously about 0% of the nuclease activity of the non-mutated or wild type Cpf1 enzyme or CRISPR enzyme, or no more than about 3% or about 5% or about 10% of the nuclease activity of the non-mutated or wild type Cpf1 enzyme, e.g. of the non-mutated or wild type Francisella novicida U112 (FnCpf1), Acidaminococcus sp. BV3L6 (AsCpf1), Lachnospiraceae bacterium ND2006 (LbCpf1) or Moraxella bovoculi 237 (MbCpf1) Cpf1 enzyme or CRISPR enzyme. This is possible by introducing mutations into the nuclease domains of the Cpf1 and orthologs thereof

In certain embodiments, the CRISPR enzyme is engineered and can comprise one or more mutations that reduce or eliminate a nuclease activity. The amino acid positions in the FnCpf1p RuvC domain include but are not limited to D917A, E1006A, E1028A, D1227A, D1255A, N1257A, D917A, E1006A, E1028A, D1227A, D1255A and N1257A. Applicants have also identified a putative second nuclease domain which is most similar to PD-(D/E)XK nuclease superfamily and HincII endonuclease like. The point mutations to be generated in this putative nuclease domain to substantially reduce nuclease activity include but are not limited to N580A, N584A, T587A, W609A, D610A, K613A, E614A, D616A, K624A, D625A, K627A and Y629A. In a preferred embodiment, the mutation in the FnCpf1p RuvC domain is D917A or E1006A, wherein the D917A or E1006A mutation completely inactivates the DNA cleavage activity of the FnCpf1 effector protein. In another embodiment, the mutation in the FnCpf1p RuvC domain is D1255A, wherein the mutated FnCpf1 effector protein has significantly reduced nucleolytic activity.

More particularly, the inactivated Cpf1 enzymes include enzymes mutated in amino acid positions As908, As993, As1263 of AsCpf1 or corresponding positions in Cpf1 orthologs. Additionally, the inactivated Cpf1 enzymes include enzymes mutated in amino acid position Lb832, 925, 947 or 1180 of LbCpf1 or corresponding positions in Cpf1 orthologs. More particularly, the inactivated Cpf1 enzymes include enzymes comprising one or more of mutations AsD908A, AsE993A, AsD1263A of AsCpf1 or corresponding mutations in Cpf1 orthologs. Additionally, the inactivated Cpf1 enzymes include enzymes comprising one or more of mutations LbD832A, E925A, D947A or D1180A of LbCpf1 or corresponding mutations in Cpf1 orthologs.

Mutations can also be made at neighboring residues, e.g., at amino acids near those indicated above that participate in the nuclease activity. In some embodiments, only the RuvC domain is inactivated, and in other embodiments, another putative nuclease domain is inactivated, wherein the effector protein complex functions as a nickase and cleaves only one DNA strand. In a preferred embodiment, the other putative nuclease domain is a HincII-like endonuclease domain. In some embodiments, two FnCpf1, AsCpf1 or LbCpf1 variants (each a different nickase) are used to increase specificity, two nickase variants are used to cleave DNA at a target (where both nickases cleave a DNA strand, while minimizing or eliminating off-target modifications where only one DNA strand is cleaved and subsequently repaired). In preferred embodiments the Cpf1 effector protein cleaves sequences associated with or at a target locus of interest as a homodimer comprising two Cpf1 effector protein molecules. In a preferred embodiment the homodimer may comprise two Cpf1 effector protein molecules comprising a different mutation in their respective RuvC domains.

The inactivated Cpf1 CRISPR enzyme may have associated (e.g., via fusion protein) one or more functional domains, including for example, one or more domains from the group comprising, consisting essentially of, or consisting of methylase activity, demethylase activity, transcription activation activity, transcription repression activity, transcription release factor activity, histone modification activity, RNA cleavage activity, DNA cleavage activity, nucleic acid binding activity, and molecular switches (e.g., light inducible). Preferred domains are Fok1, VP64, P65, HSF1, MyoD1. In the event that Fok1 is provided, it is advantageous that multiple Fok1 functional domains are provided to allow for a functional dimer and that gRNAs are designed to provide proper spacing for functional use (Fok1) as specifically described in Tsai et al. Nature Biotechnology, Vol. 32, Number 6, June 2014). The adaptor protein may utilize known linkers to attach such functional domains. In some cases it is advantageous that additionally at least one NLS is provided. In some instances, it is advantageous to position the NLS at the N terminus. When more than one functional domain is included, the functional domains may be the same or different.

In general, the positioning of the one or more functional domain on the inactivated Cpf1 enzyme is one which allows for correct spatial orientation for the functional domain to affect the target with the attributed functional effect. For example, if the functional domain is a transcription activator (e.g., VP64 or p65), the transcription activator is placed in a spatial orientation which allows it to affect the transcription of the target. Likewise, a transcription repressor will be advantageously positioned to affect the transcription of the target, and a nuclease (e.g., Fok1) will be advantageously positioned to cleave or partially cleave the target. This may include positions other than the N-/C-terminus of the CRISPR enzyme.

Elements of the Nuclear Targeting System

In general, “nucleic acid-targeting system” as used in the present application refers collectively to transcripts and other elements involved in the expression of or directing the activity of nucleic acid-targeting CRISPR-associated (“Cas”) genes (also referred to herein as an effector protein), including sequences encoding a nucleic acid-targeting Cas (effector) protein and a guide RNA (comprising crRNA sequence and a trans-activating CRISPR/Cas system RNA (tracrRNA) sequence), or other sequences and transcripts from a nucleic acid-targeting CRISPR locus. In some embodiments, one or more elements of a nucleic acid-targeting system are derived from a Type V/Type VI nucleic acid-targeting CRISPR system. In some embodiments, one or more elements of a nucleic acid-targeting system is derived from a particular organism comprising an endogenous nucleic acid-targeting CRISPR system. In general, a nucleic acid-targeting system is characterized by elements that promote the formation of a nucleic acid-targeting complex at the site of a target sequence. In the context of formation of a nucleic acid-targeting complex, “target sequence” refers to a sequence to which a guide sequence is designed to have complementarity, where hybridization between a target sequence and a guide RNA promotes the formation of a DNA or RNA-targeting complex. Full complementarity is not necessarily required, provided there is sufficient complementarity to cause hybridization and promote formation of a nucleic acid-targeting complex. A target sequence may comprise RNA polynucleotides. In some embodiments, a target sequence is located in the nucleus or cytoplasm of a cell. In some embodiments, the target sequence may be within an organelle of a eukaryotic cell, for example, mitochondrion or chloroplast. A sequence or template that may be used for recombination into the targeted locus comprising the target sequences is referred to as an “editing template” or “editing RNA” or “editing sequence”. In aspects of the invention, an exogenous template RNA may be referred to as an editing template. In an aspect of the invention the recombination is homologous recombination.

Typically, in the context of an endogenous nucleic acid-targeting system, formation of a nucleic acid-targeting complex (comprising a guide RNA hybridized to a target sequence and complexed with one or more nucleic acid-targeting effector proteins) results in cleavage of one or both RNA strands in or near (e.g. within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from) the target sequence. In some embodiments, one or more vectors driving expression of one or more elements of a nucleic acid-targeting system are introduced into a host cell such that expression of the elements of the nucleic acid-targeting system direct formation of a nucleic acid-targeting complex at one or more target sites. For example, a nucleic acid-targeting effector protein and a guide RNA could each be operably linked to separate regulatory elements on separate vectors. Alternatively, two or more of the elements expressed from the same or different regulatory elements, may be combined in a single vector, with one or more additional vectors providing any components of the nucleic acid-targeting system not included in the first vector. Nucleic acid-targeting system elements that are combined in a single vector may be arranged in any suitable orientation, such as one element located 5′ with respect to (“upstream” of) or 3′ with respect to (“downstream” of) a second element. The coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and oriented in the same or opposite direction. In some embodiments, a single promoter drives expression of a transcript encoding a nucleic acid-targeting effector protein and a guide RNA embedded within one or more intron sequences (e.g. each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the nucleic acid-targeting effector protein and guide RNA are operably linked to and expressed from the same promoter.

In general, a CRISPR system is characterized by elements that promote the formation of a CRISPR complex at the site of a target sequence (also referred to as a protospacer in the context of an endogenous CRISPR system). In the context of formation of a CRISPR complex, “target sequence” refers to a sequence to which a guide sequence is designed to target, e.g. have complementarity, where hybridization between a target sequence and a guide sequence promotes the formation of a CRISPR complex. The section of the guide sequence through which complementarity to the target sequence is important for cleavage activity is referred to herein as the seed sequence. A target sequence may comprise any polynucleotide, such as DNA or RNA polynucleotides and is comprised within a target locus of interest. In some embodiments, a target sequence is located in the nucleus or cytoplasm of a cell.

In general, the term “guide sequence” is any polynucleotide sequence having sufficient complementarity with a target polynucleotide sequence to hybridize with the target sequence and direct sequence-specific binding of a nucleic acid-targeting complex to the target sequence. In some embodiments, the degree of complementarity between a guide sequence and its corresponding target sequence, when optimally aligned using a suitable alignment algorithm, is about or more than about 50%, 60%, 75%, 80%, 85%, 90%, 95%, 97.5%, 99%, or more. Optimal alignment may be determined with the use of any suitable algorithm for aligning sequences, non-limiting example of which include the Smith-Waterman algorithm, the Needleman-Wunsch algorithm, algorithms based on the Burrows-Wheeler Transform (e.g. the Burrows Wheeler Aligner), ClustalW, Clustal X, BLAT, Novoalign (Novocraft Technologies, ELAND (Illumina, San Diego, Calif.), SOAP (available at soap.genomics.org.cn), and Maq (available at maq.sourceforge.net). In some embodiments, a guide sequence is about or more than about 5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 75, or more nucleotides in length. In some embodiments, a guide sequence is less than about 75, 50, 45, 40, 35, 30, 25, 20, 15, 12, or fewer nucleotides in length. The ability of a guide sequence to direct sequence-specific binding of a nucleic acid-targeting complex to a target sequence may be assessed by any suitable assay (as described in EP3009511 or US2016208243). For example, the components of a nucleic acid-targeting system sufficient to form a nucleic acid-targeting complex, including the guide sequence to be tested, may be provided to a host cell having the corresponding target sequence, such as by transfection with vectors encoding the components of the nucleic acid-targeting CRISPR sequence, followed by an assessment of preferential cleavage within or in the vicinity of the target sequence, such as by Surveyor assay as described herein. Similarly, cleavage of a target polynucleotide sequence (or a sequence in the vicinity thereof) may be evaluated in a test tube by providing the target sequence, components of a nucleic acid-targeting complex, including the guide sequence to be tested and a control guide sequence different from the test guide sequence, and comparing binding or rate of cleavage at or in the vicinity of the target sequence between the test and control guide sequence reactions. Other assays are possible, and will occur to those skilled in the art.

A guide sequence may be selected to target any target sequence. In some embodiments, the target sequence is a sequence within a gene transcript or mRNA. In some embodiments, the target sequence is a sequence within a genome of a cell.

In some embodiments, a guide sequence is selected to reduce the degree of secondary structure within the guide sequence. Secondary structure may be determined by any suitable polynucleotide folding algorithm. Some programs are based on calculating the minimal Gibbs free energy. An example of one such algorithm is mFold, as described by Zuker and Stiegler (Nucleic Acids Res. 9 (1981), 133-148). Another example folding algorithm is the online webserver RNAfold, developed at Institute for Theoretical Chemistry at the University of Vienna, using the centroid structure prediction algorithm (see e.g. A. R. Gruber et al., 2008 , Cell 106(1): 23-24; and P A Can and G M Church, 2009 , Nature Biotechnology 27(12): 1151-62). Further algorithms may be found in U.S. application Ser. No. —————— ; incorporated herein by reference.

In certain embodiments, a guide RNA or crRNA may comprise, consist essentially of, or consist of a direct repeat (DR) sequence and a guide sequence or spacer sequence. In certain embodiments, the guide RNA or crRNA may comprise, consist essentially of, or consist of a direct repeat sequence fused or linked to a guide sequence or spacer sequence. In certain embodiments, the direct repeat sequence may be located upstream (i.e., 5′) from the guide sequence or spacer sequence. In other embodiments, the direct repeat sequence may be located downstream (i.e., 3′) from the guide sequence or spacer sequence. For the Cpf1 orthologs identified to date, the direct repeat is located upstream 5′ of the guide sequence.

In relation to a nucleic acid-targeting complex or system preferably, the crRNA sequence has one or more stem loops or hairpins and is 30 or more nucleotides in length, 40 or more nucleotides in length, or 50 or more nucleotides in length. In certain embodiments, the crRNA sequence is between 42 and 44 nucleotides in length, and the nucleic acid-targeting Cas protein is Cpf1 of Francisella tularensis subsp. novicida U112. In certain embodiments, the crRNA comprises, consists essentially of, or consists of 19 nucleotides of a direct repeat and between 23 and 25 nucleotides of spacer sequence, and the nucleic acid-targeting Cas protein is Cpf1 of Francisella tularensis subsp. novocida U112.

In certain embodiments, the crRNA comprises a stem loop, preferably a single stem loop. In certain embodiments, the direct repeat sequence forms a stem loop, preferably a single stem loop.

In certain embodiments, the spacer length of the guide RNA is from 15 to 35 nt. In certain embodiments, the spacer length of the guide RNA is at least 15 nucleotides. In certain embodiments, the spacer length is from 15 to 17 nt, e.g., 15, 16, or 17 nt, from 17 to 20 nt, e.g., 17, 18, 19, or 20 nt, from 20 to 24 nt, e.g., 20, 21, 22, 23, or 24 nt, from 23 to 25 nt, e.g., 23, 24, or 25 nt, from 24 to 27 nt, e.g., 24, 25, 26, or 27 nt, from 27-30 nt, e.g., 27, 28, 29, or 30 nt, from 30-35 nt, e.g., 30, 31, 32, 33, 34, or 35 nt, or 35 nt or longer.

In some embodiments, the direct repeat has a minimum length of 16 nts and a single stem loop. In further embodiments the direct repeat has a length longer than 16 nts, preferably more than 17 nts, and has more than one stem loop or optimized secondary structures. In some embodiments, the guide sequence is at least 16, 17, 18, 19, 20, 25 nucleotides, or between 16-30, or between 16-25, or between 16-20 nucleotides in length.

In some embodiments, direct repeats may be identified in silico by searching for repetitive motifs that fulfill any or all of the following criteria: 1. found in a 2Kb window of genomic sequence flanking the type II CRISPR locus; 2. span from 20 to 50 bp; and 3. interspaced by 20 to 50 bp. In some embodiments, 2 of these criteria may be used, for instance 1 and 2, 2 and 3, or 1 and 3. In some embodiments, all 3 criteria may be used.

The “tracrRNA” sequence or analogous terms includes any polynucleotide sequence that has sufficient complementarity with a crRNA sequence to hybridize. As indicated herein above, in embodiments of the present invention, the tracrRNA is not required for cleavage activity of Cpf1 effector protein complexes.

In some embodiments, the nucleic acid-targeting effector protein is part of a fusion protein comprising one or more heterologous protein domains (e.g., about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more domains in addition to the nucleic acid-targeting effector protein). In some embodiments, the CRISPR effector protein is part of a fusion protein comprising one or more heterologous protein domains (e.g. about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more domains in addition to the CRISPR enzyme). A CRISPR enzyme fusion protein may comprise any additional protein sequence, and optionally a linker sequence between any two domains. Examples of protein domains that may be fused to a CRISPR enzyme include, without limitation, epitope tags, reporter gene sequences, and protein domains having one or more of the following activities: methylase activity, demethylase activity, transcription activation activity, transcription repression activity, transcription release factor activity, histone modification activity, RNA cleavage activity and nucleic acid binding activity. Non-limiting examples of epitope tags include histidine (His) tags, V5 tags, FLAG tags, influenza hemagglutinin (HA) tags, Myc tags, VSV-G tags, and thioredoxin (Trx) tags. Examples of reporter genes include, but are not limited to, glutathione-S-transferase (GST), horseradish peroxidase (HRP), chloramphenicol acetyltransferase (CAT) beta-galactosidase, beta-glucuronidase, luciferase, green fluorescent protein (GFP), HcRed, DsRed, cyan fluorescent protein (CFP), yellow fluorescent protein (YFP), and autofluorescent proteins including blue fluorescent protein (BFP). A CRISPR enzyme may be fused to a gene sequence encoding a protein or a fragment of a protein that bind DNA molecules or bind other cellular molecules, including but not limited to maltose binding protein (MBP), S-tag, Lex A DNA binding domain (DBD) fusions, GAL4 DNA binding domain fusions, and herpes simplex virus (HSV) BP16 protein fusions. Additional domains that may form part of a fusion protein comprising a CRISPR enzyme are described in US20110059502, incorporated herein by reference. In some embodiments, a tagged CRISPR enzyme is used to identify the location of a target sequence.

In some embodiments, a CRISPR enzyme may form a component of an inducible system. The inducible nature of the system would allow for spatiotemporal control of gene editing or gene expression using a form of energy. The form of energy may include but is not limited to electromagnetic radiation, sound energy, chemical energy and thermal energy. Examples of inducible system include tetracycline inducible promoters (Tet-On or Tet-Off), small molecule two-hybrid transcription activations systems (FKBP, ABA, etc), or light inducible systems (Phytochrome, LOV domains, or cryptochrome),In one embodiment, the CRISPR enzyme may be a part of a Light Inducible Transcriptional Effector (LITE) to direct changes in transcriptional activity in a sequence-specific manner. The components of a light may include a CRISPR enzyme, a light-responsive cytochrome heterodimer (e.g. from Arabidopsis thaliana ), and a transcriptional activation/repression domain. Further examples of inducible DNA binding proteins and methods for their use are provided in U.S. 61/736,465 and U.S. 61/721,283 and WO 2014/018423 and U.S. Pat. Nos. 8,889,418, 8,895,308, US20140186919, US20140242700, US20140273234, US20140335620, WO2014093635, which is hereby incorporated by reference in its entirety.

In some embodiments, a recombination template is also provided. A recombination template may be a component of another vector as described herein, contained in a separate vector, or provided as a separate polynucleotide. In some embodiments, a recombination template is designed to serve as a template in homologous recombination, such as within or near a target sequence nicked or cleaved by a nucleic acid-targeting effector protein as a part of a nucleic acid-targeting complex.

In an embodiment, the template nucleic acid alters the sequence of the target position. In an embodiment, the template nucleic acid results in the incorporation of a modified, or non-naturally occurring base into the target nucleic acid.

The template sequence may undergo a breakage mediated or catalyzed recombination with the target sequence. In an embodiment, the template nucleic acid may include sequence that corresponds to a site on the target sequence that is cleaved by an Cpf1 mediated cleavage event. In an embodiment, the template nucleic acid may include sequence that corresponds to both, a first site on the target sequence that is cleaved in a first Cpf1 mediated event, and a second site on the target sequence that is cleaved in a second Cpf1 mediated event.

In certain embodiments, the template nucleic acid can include sequence which results in an alteration in the coding sequence of a translated sequence, e.g., one which results in the substitution of one amino acid for another in a protein product, e.g., transforming a mutant allele into a wild type allele, transforming a wild type allele into a mutant allele, and/or introducing a stop codon, insertion of an amino acid residue, deletion of an amino acid residue, or a nonsense mutation. In certain embodiments, the template nucleic acid can include sequence which results in an alteration in a non-coding sequence, e.g., an alteration in an exon or in a 5′ or 3′ non-translated or non-transcribed region. Such alterations include an alteration in a control element, e.g., a promoter, enhancer, and an alteration in a cis-acting or trans-acting control element.

A template nucleic acid having homology with a target position in a target gene may be used to alter the structure of a target sequence. The template sequence may be used to alter an unwanted structure, e.g., an unwanted or mutant nucleotide. The template nucleic acid may include sequence which, when integrated, results in: decreasing the activity of a positive control element; increasing the activity of a positive control element; decreasing the activity of a negative control element; increasing the activity of a negative control element; decreasing the expression of a gene; increasing the expression of a gene; increasing resistance to a disorder or disease; increasing resistance to viral entry; correcting a mutation or altering an unwanted amino acid residue conferring, increasing, abolishing or decreasing a biological property of a gene product, e.g., increasing the enzymatic activity of an enzyme, or increasing the ability of a gene product to interact with another molecule.

The template nucleic acid may include sequence which results in: a change in sequence of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more nucleotides of the target sequence.

A template polynucleotide may be of any suitable length, such as about or more than about 10, 15, 20, 25, 50, 75, 100, 150, 200, 500, 1000, or more nucleotides in length. In an embodiment, the template nucleic acid may be 20+/−10, 30+/−10, 40+/−10, 50+/−10, 60+/−10, 70+/−10, 80+/−10, 90+/−10, 100+/−10, 1 10+/−10, 120+/−10, 130+/−10, 140+/−10, 150+/−10, 160+/−10, 170+/−10, 1 80+/−10, 190+/−10, 200+/−10, 210+/−10, of 220+/−10 nucleotides in length. In an embodiment, the template nucleic acid may be 30+/−20, 40+/−20, 50+/−20, 60+/−20, 70+/−20, 80+/−20, 90+/−20, 100+/−20, 1 10+/−20, 120+/−20, 130+/−20, 140+/−20, I 50+/−20, 160+/−20, 170+/−20, 180+/−20, 190+/−20, 200+/−20, 210+/−20, of 220+/−20 nucleotides in length. In an embodiment, the template nucleic acid is 10 to 1,000, 20 to 900, 30 to 800, 40 to 700, 50 to 600, 50 to 500, 50 to 400, 50 to 300, 50 to 200, or 50 to 100 nucleotides in length.

In some embodiments, the template polynucleotide is complementary to a portion of a polynucleotide comprising the target sequence. When optimally aligned, a template polynucleotide might overlap with one or more nucleotides of a target sequences (e.g. about or more than about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100 or more nucleotides). In some embodiments, when a template sequence and a polynucleotide comprising a target sequence are optimally aligned, the nearest nucleotide of the template polynucleotide is within about 1, 5, 10, 15, 20, 25, 50, 75, 100, 200, 300, 400, 500, 1000, 5000, 10000, or more nucleotides from the target sequence.

The exogenous polynucleotide template comprises a sequence to be integrated (e.g., a mutated gene). The sequence for integration may be a sequence endogenous or exogenous to the cell. Examples of a sequence to be integrated include polynucleotides encoding a protein or a non-coding RNA (e.g., a microRNA). Thus, the sequence for integration may be operably linked to an appropriate control sequence or sequences. Alternatively, the sequence to be integrated may provide a regulatory function.

An upstream or downstream sequence may comprise from about 20 bp to about 2500 bp, for example, about 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, or 2500 bp. In some methods, the exemplary upstream or downstream sequence have about 200 bp to about 2000 bp, about 600 bp to about 1000 bp, or more particularly about 700 bp to about 1000.

An upstream or downstream sequence may comprise from about 20 bp to about 2500 bp, for example, about 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, or 2500 bp. In some methods, the exemplary upstream or downstream sequence have about 200 bp to about 2000 bp, about 600 bp to about 1000 bp, or more particularly about 700 bp to about 1000.

In certain embodiments, one or both homology arms may be shortened to avoid including certain sequence repeat elements. For example, a 5′ homology arm may be shortened to avoid a sequence repeat element. In other embodiments, a 3′ homology arm may be shortened to avoid a sequence repeat element. In some embodiments, both the 5′ and the 3′ homology arms may be shortened to avoid including certain sequence repeat elements.

In some methods, the exogenous polynucleotide template may further comprise a marker. Such a marker may make it easy to screen for targeted integrations. Examples of suitable markers include restriction sites, fluorescent proteins, or selectable markers. The exogenous polynucleotide template of the invention can be constructed using recombinant techniques (see, for example, Sambrook et al., 2001 and Ausubel et al., 1996).

In certain embodiments, a template nucleic acids for correcting a mutation may designed for use as a single-stranded oligonucleotide. When using a single-stranded oligonucleotide, 5′ and 3′ homology arms may range up to about 200 base pairs (bp) in length, e.g., at least 25, 50, 75, 100, 125, 150, 175, or 200 bp in length.

Suzuki et al. describe in vivo genome editing via CRISPR/Cas9 mediated homology-independent targeted integration (2016, Nature 540:144-149).

Accordingly, when referring to the CRISPR system herein, in some aspects or embodiments, the CRISPR system comprises (i) a CRISPR protein or a polynucleotide encoding a CRISPR effector protein and (ii) one or more polynucleotides engineered to: complex with the CRISPR protein to form a CRISPR complex; and to complex with the target sequence.

In some embodiments, the therapeutic is for delivery (or application or administration) to a eukaryotic cell, either in vivo or ex vivo.

In some embodiments, the CRISPR protein is a nuclease directing cleavage of one or both strands at the location of the target sequence, or wherein the CRISPR protein is a nickase directing cleavage at the location of the target sequence.

In some embodiments, the CRISPR protein is a Cpf1 protein complexed with a CRISPR-Cas system RNA polynucleotide sequence, wherein the polynucleotide sequence comprises: a) a guide RNA polynucleotide capable of hybridizing to a target HBV sequence; and (b) a direct repeat RNA polynucleotide.

In some embodiments, the CRISPR protein is a Cpf1, and the system comprises: I. a CRISPR-Cas system RNA polynucleotide sequence, wherein the polynucleotide sequence comprises: (a) a guide RNA polynucleotide capable of hybridizing to a target sequence, and (b) a direct repeat RNA polynucleotide, and II. a polynucleotide sequence encoding the Cpf1, optionally comprising at least one or more nuclear localization sequences, wherein the direct repeat sequence hybridizes to the guide sequence and directs sequence-specific binding of a CRISPR complex to the target sequence, and wherein the CRISPR complex comprises the CRISPR protein complexed with (1) the guide sequence that is hybridized or hybridizable to the target sequence, and (2) the direct repeat sequence, and the polynucleotide sequence encoding a CRISPR protein is DNA or RNA.

In some embodiments, the CRISPR protein is a Cpf1 from Acidaminococcus sp. BV3L6 (AsCpf1), Lachnospiraceae bacterium ND2006 (LbCpf1) or Moraxella bovoculi 237.

In some embodiments, the CRISPR protein further comprises one or more nuclear localization sequences (NLSs) capable of driving the accumulation of the CRISPR protein to a detectible amount in the nucleus of the cell of the organism.

In some embodiments, the CRISPR protein comprises one or more mutations.

In some embodiments, he CRISPR protein has one or more mutations in a catalytic domain, and wherein the protein further comprises a functional domain.

In some embodiments, the CRISPR system is comprised within a delivery system, optionally: a vector system comprising one or more vectors, optionally wherein the vectors comprise one or more viral vectors, optionally wherein the one or more viral vectors comprise one or more lentiviral, adenoviral or adeno-associated viral (AAV) vectors; or a particle or lipid particle, optionally wherein the CRISPR protein is complexed with the polynucleotides to form the CRISPR complex.

In some embodiments, the system, complex or protein is for use in a method of modifying an organism or a non-human organism by manipulation of a target sequence in a genomic locus of interest.

In some embodiments, the polynucleotides encoding the sequence encoding or providing the CRISPR system are delivered via liposomes, particles, cell penetrating peptides, exosomes, microvesicles, or a gene-gun. In some embodiments, a delivery system is included. In some embodiments, the delivery system comprises: a vector system comprising one or more vectors comprising the engineered polynucleotides and polynucleotide encoding the CRISPR protein, optionally wherein the vectors comprise one or more viral vectors, optionally wherein the one or more viral vectors comprise one or more lentiviral, adenoviral or adeno-associated viral (AAV) vectors; or a particle or lipid particle, containing the CRISPR system or the CRISPR complex.

In some embodiments, the CRISPR protein has one or more mutations in a catalytic domain, and wherein the enzyme further comprises a functional domain.

In some embodiments, a recombination/repair template is provided.

Cpf1 Vectors (10083)

In general, and throughout this specification, the term “vector” refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. It is a replicon, such as a plasmid, phage, or cosmid, into which another DNA segment may be inserted so as to bring about the replication of the inserted segment. Generally, a vector is capable of replication when associated with the proper control elements.

Vectors include, but are not limited to, nucleic acid molecules that are single-stranded, double-stranded, or partially double-stranded; nucleic acid molecules that comprise one or more free ends, no free ends (e.g., circular); nucleic acid molecules that comprise DNA, RNA, or both; and other varieties of polynucleotides known in the art. One type of vector is a “plasmid,” which refers to a circular double stranded DNA loop into which additional DNA segments can be inserted, such as by standard molecular cloning techniques. Another type of vector is a viral vector, wherein virally-derived DNA or RNA sequences are present in the vector for packaging into a virus (e.g., retroviruses, replication defective retroviruses, adenoviruses, replication defective adenoviruses, and adeno-associated viruses). Viral vectors also include polynucleotides carried by a virus for transfection into a host cell. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) are integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, certain vectors are capable of directing the expression of genes to which they are operatively-linked. Such vectors are referred to herein as “expression vectors.” Vectors for and that result in expression in a eukaryotic cell can be referred to herein as “eukaryotic expression vectors.” Common expression vectors of utility in recombinant DNA techniques are often in the form of plasmids.

Recombinant expression vectors can comprise a nucleic acid of the invention in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed. Within a recombinant expression vector, “operably linked” is intended to mean that the nucleotide sequence of interest is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence (e.g., in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell). Advantageous vectors include lentiviruses and adeno-associated viruses, and types of such vectors can also be selected for targeting particular types of cells.

With regards to recombination and cloning methods, mention is made of U.S. patent application Ser. No. 10/815,730, published Sep. 2, 2004 as US 2004-0171156 A1, the contents of which are herein incorporated by reference in their entirety.

The term “regulatory element” is intended to include promoters, enhancers, internal ribosomal entry sites (IRES), and other expression control elements (e.g., transcription termination signals, such as polyadenylation signals and poly-U sequences). Such regulatory elements are described, for example, in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Regulatory elements include those that direct constitutive expression of a nucleotide sequence in many types of host cell and those that direct expression of the nucleotide sequence only in certain host cells (e.g., tissue-specific regulatory sequences). A tissue-specific promoter may direct expression primarily in a desired tissue of interest, such as muscle, neuron, bone, skin, blood, specific organs (e.g., liver, pancreas), or particular cell types (e.g., lymphocytes). Regulatory elements may also direct expression in a temporal-dependent manner, such as in a cell-cycle dependent or developmental stage-dependent manner, which may or may not also be tissue or cell-type specific. In some embodiments, a vector comprises one or more pol III promoter (e.g., 1, 2, 3, 4, 5, or more pol III promoters), one or more pol II promoters (e.g., 1, 2, 3, 4, 5, or more pol II promoters), one or more pol I promoters (e.g., 1, 2, 3, 4, 5, or more pol I promoters), or combinations thereof. Examples of pol III promoters include, but are not limited to, U6 and H1 promoters. Examples of pol II promoters include, but are not limited to, the retroviral Rous sarcoma virus (RSV) LTR promoter (optionally with the RSV enhancer), the cytomegalovirus (CMV) promoter (optionally with the CMV enhancer) [see, e.g., Boshart et al, Cell, 41:521-530 (1985)], the SV40 promoter, the dihydrofolate reductase promoter, the β-actin promoter, the phosphoglycerol kinase (PGK) promoter, and the EF1α promoter. Also encompassed by the term “regulatory element” are enhancer elements, such as WPRE; CMV enhancers; the R-U5′ segment in LTR of HTLV-I (Mol. Cell. Biol., Vol. 8(1), p. 466-472, 1988); SV40 enhancer; and the intron sequence between exons 2 and 3 of rabbit β-globin (Proc. Natl. Acad. Sci. USA., Vol. 78(3), p. 1527-31, 1981). It will be appreciated by those skilled in the art that the design of the expression vector can depend on such factors as the choice of the host cell to be transformed, the level of expression desired, etc. A vector can be introduced into host cells to thereby produce transcripts, proteins, or peptides, including fusion proteins or peptides, encoded by nucleic acids as described herein (e.g., clustered regularly interspersed short palindromic repeats (CRISPR) transcripts, proteins, enzymes, mutant forms thereof, fusion proteins thereof, etc.). With regards to regulatory sequences, mention is made of U.S. patent application Ser. No. 10/491,026, the contents of which are incorporated by reference herein in their entirety. With regards to promoters, mention is made of PCT publication WO 2011/028929 and U.S. application Ser. No. 12/511,940, the contents of which are incorporated by reference herein in their entirety.

Advantageous vectors include lentiviruses and adeno-associated viruses, and types of such vectors can also be selected for targeting particular types of cells.

In particular embodiments, use is made of bicistronic vectors for guide RNA and (optionally modified or mutated) CRISPR enzymes (e.g. Cpf1). Bicistronic expression vectors for guide RNA and (optionally modified or mutated) CRISPR enzymes are preferred. In general and particularly in this embodiment (optionally modified or mutated) CRISPR enzymes are preferably driven by the CBh promoter. The RNA may preferably be driven by a Pol III promoter, such as a U6 promoter. Ideally the two are combined.

Vectors can be designed for expression of CRISPR transcripts (e.g. nucleic acid transcripts, proteins, or enzymes) in prokaryotic or eukaryotic cells. For example, CRISPR transcripts can be expressed in bacterial cells such as Escherichia coli , insect cells (using baculovirus expression vectors), yeast cells, or mammalian cells. Suitable host cells are discussed further in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Alternatively, the recombinant expression vector can be transcribed and translated in vitro, for example using T7 promoter regulatory sequences and T7 polymerase.

Vectors may be introduced and propagated in a prokaryote or prokaryotic cell. In some embodiments, a prokaryote is used to amplify copies of a vector to be introduced into a eukaryotic cell or as an intermediate vector in the production of a vector to be introduced into a eukaryotic cell (e.g. amplifying a plasmid as part of a viral vector packaging system). In some embodiments, a prokaryote is used to amplify copies of a vector and express one or more nucleic acids, such as to provide a source of one or more proteins for delivery to a host cell or host organism. Expression of proteins in prokaryotes is most often carried out in Escherichia coli with vectors containing constitutive or inducible promoters directing the expression of either fusion or non-fusion proteins. Fusion vectors add a number of amino acids to a protein encoded therein, such as to the amino terminus of the recombinant protein. Such fusion vectors may serve one or more purposes, such as: (i) to increase expression of recombinant protein; (ii) to increase the solubility of the recombinant protein; and (iii) to aid in the purification of the recombinant protein by acting as a ligand in affinity purification. Often, in fusion expression vectors, a proteolytic cleavage site is introduced at the junction of the fusion moiety and the recombinant protein to enable separation of the recombinant protein from the fusion moiety subsequent to purification of the fusion protein. Such enzymes, and their cognate recognition sequences, include Factor Xa, thrombin and enterokinase. Example fusion expression vectors include pGEX (Pharmacia Biotech Inc; Smith and Johnson, 1988. Gene 67: 31-40), pMAL (New England Biolabs, Beverly, Mass.) and pRIT5 (Pharmacia, Piscataway, N.J.) that fuse glutathione S-transferase (GST), maltose E binding protein, or protein A, respectively, to the target recombinant protein. Examples of suitable inducible non-fusion E. coli expression vectors include pTrc (Amrann et al., (1988) Gene 69:301-315) and pET 11d (Studier et al., GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990) 60-89). In some embodiments, a vector is a yeast expression vector. Examples of vectors for expression in yeast Saccharomyces cerevisiae include pYepSec1 (Baldari, et al., 1987. EMBO J. 6: 229-234), pMFa (Kuijan and Herskowitz, 1982. Cell 30: 933-943), pJRY88 (Schultz et al., 1987. Gene 54: 113-123), pYES2 (Invitrogen Corporation, San Diego, Calif.), and picZ (InVitrogen Corp, San Diego, Calif.). In some embodiments, a vector drives protein expression in insect cells using baculovirus expression vectors. Baculovirus vectors available for expression of proteins in cultured insect cells (e.g., SF9 cells) include the pAc series (Smith, et al., 1983. Mol. Cell. Biol. 3: 2156-2165) and the pVL series (Lucklow and Summers, 1989. Virology 170: 31-39).

In some embodiments, a vector is capable of driving expression of one or more sequences in mammalian cells using a mammalian expression vector. Examples of mammalian expression vectors include pCDM8 (Seed, 1987. Nature 329: 840) and pMT2PC (Kaufman, et al., 1987. EMBO J. 6: 187-195). When used in mammalian cells, the expression vector's control functions are typically provided by one or more regulatory elements. For example, commonly used promoters are derived from polyoma, adenovirus 2, cytomegalovirus, simian virus 40, and others disclosed herein and known in the art. For other suitable expression systems for both prokaryotic and eukaryotic cells see, e.g., Chapters 16 and 17 of Sambrook, et al., MOLECULAR CLONING: A LABORATORY MANUAL. 2nd ed., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989.

In some embodiments, the recombinant mammalian expression vector is capable of directing expression of the nucleic acid preferentially in a particular cell type (e.g., tissue-specific regulatory elements are used to express the nucleic acid). Tissue-specific regulatory elements are known in the art. Non-limiting examples of suitable tissue-specific promoters include the albumin promoter (liver-specific; Pinkert, et al., 1987. Genes Dev. 1: 268-277), lymphoid-specific promoters (Calame and Eaton, 1988. Adv. Immunol. 43: 235-275), in particular promoters of T cell receptors (Winoto and Baltimore, 1989. EMBO J. 8: 729-733) and immunoglobulins (Baneiji, et al., 1983. Cell 33: 729-740; Queen and Baltimore, 1983. Cell 33: 741-748), neuron-specific promoters (e.g., the neurofilament promoter; Byrne and Ruddle, 1989. Proc. Natl. Acad. Sci. USA 86: 5473-5477), pancreas-specific promoters (Edlund, et al., 1985. Science 230: 912-916), and mammary gland-specific promoters (e.g., milk whey promoter; U.S. Pat. No. 4,873,316 and European Application Publication No. 264,166). Developmentally-regulated promoters are also encompassed, e.g., the murine hox promoters (Kessel and Gruss, 1990. Science 249: 374-379) and the a-fetoprotein promoter (Campes and Tilghman, 1989. Genes Dev. 3: 537-546). With regards to these prokaryotic and eukaryotic vectors, mention is made of U.S. Pat. No. 6,750,059, the contents of which are incorporated by reference herein in their entirety. Other embodiments of the invention may relate to the use of viral vectors, with regards to which mention is made of U.S. patent application Ser. No. 13/092,085, the contents of which are incorporated by reference herein in their entirety. Tissue-specific regulatory elements are known in the art and in this regard, mention is made of U.S. Pat. No. 7,776,321, the contents of which are incorporated by reference herein in their entirety. In some embodiments, a regulatory element is operably linked to one or more elements of a CRISPR system so as to drive expression of the one or more elements of the CRISPR system.

In some embodiments, one or more vectors driving expression of one or more elements of a nucleic acid-targeting system are introduced into a host cell such that expression of the elements of the nucleic acid-targeting system direct formation of a nucleic acid-targeting complex at one or more target sites. For example, a nucleic acid-targeting effector enzyme and a nucleic acid-targeting guide RNA could each be operably linked to separate regulatory elements on separate vectors. RNA(s) of the nucleic acid-targeting system can be delivered to a transgenic nucleic acid-targeting effector protein animal or mammal, e.g., an animal or mammal that constitutively or inducibly or conditionally expresses nucleic acid-targeting effector protein; or an animal or mammal that is otherwise expressing nucleic acid-targeting effector proteins or has cells containing nucleic acid-targeting effector proteins, such as by way of prior administration thereto of a vector or vectors that code for and express in vivo nucleic acid-targeting effector proteins. Alternatively, two or more of the elements expressed from the same or different regulatory elements, may be combined in a single vector, with one or more additional vectors providing any components of the nucleic acid-targeting system not included in the first vector. Nucleic acid-targeting system elements that are combined in a single vector may be arranged in any suitable orientation, such as one element located 5′ with respect to (“upstream” of) or 3′ with respect to (“downstream” of) a second element. The coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and oriented in the same or opposite direction. In some embodiments, a single promoter drives expression of a transcript encoding a nucleic acid-targeting effector protein and the nucleic acid-targeting guide RNA, embedded within one or more intron sequences (e.g., each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the nucleic acid-targeting effector protein and the nucleic acid-targeting guide RNA may be operably linked to and expressed from the same promoter. Delivery vehicles, vectors, particles, nanoparticles, formulations and components thereof for expression of one or more elements of a nucleic acid-targeting system are as used in the foregoing documents, such as WO 2014/093622 (PCT/US2013/074667). In some embodiments, a vector comprises one or more insertion sites, such as a restriction endonuclease recognition sequence (also referred to as a “cloning site”). In some embodiments, one or more insertion sites (e.g., about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more insertion sites) are located upstream and/or downstream of one or more sequence elements of one or more vectors. When multiple different guide sequences are used, a single expression construct may be used to target nucleic acid-targeting activity to multiple different, corresponding target sequences within a cell. For example, a single vector may comprise about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, or more guide sequences. In some embodiments, about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more such guide-sequence-containing vectors may be provided, and optionally delivered to a cell. In some embodiments, a vector comprises a regulatory element operably linked to an enzyme-coding sequence encoding a nucleic acid-targeting effector protein. Nucleic acid-targeting effector protein or nucleic acid-targeting guide RNA or RNA(s) can be delivered separately; and advantageously at least one of these is delivered via a particle complex. Nucleic acid-targeting effector protein mRNA can be delivered prior to the nucleic acid-targeting guide RNA to give time for nucleic acid-targeting effector protein to be expressed. Nucleic acid-targeting effector protein mRNA might be administered 1-12 hours (preferably around 2-6 hours) prior to the administration of nucleic acid-targeting guide RNA. Alternatively, nucleic acid-targeting effector protein mRNA and nucleic acid-targeting guide RNA can be administered together. Advantageously, a second booster dose of guide RNA can be administered 1-12 hours (preferably around 2-6 hours) after the initial administration of nucleic acid-targeting effector protein mRNA+guide RNA. Additional administrations of nucleic acid-targeting effector protein mRNA and/or guide RNA might be useful to achieve the most efficient levels of genome modification.

In some embodiments, a vector encodes a Cpf1 effector protein comprising one or more nuclear localization sequences (NLSs), such as about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs. More particularly, vector comprises one or more NLSs not naturally present in the Cpf1 effector protein. Most particularly, the NLS is present in the vector 5′ and/or 3′ of the Cpf1 effector protein sequence In some embodiments, the RNA-targeting effector protein comprises about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs at or near the amino-terminus, about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs at or near the carboxy-terminus, or a combination of these (e.g., zero or at least one or more NLS at the amino-terminus and zero or at one or more NLS at the carboxy terminus). When more than one NLS is present, each may be selected independently of the others, such that a single NLS may be present in more than one copy and/or in combination with one or more other NLSs present in one or more copies. In some embodiments, an NLS is considered near the N- or C-terminus when the nearest amino acid of the NLS is within about 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, or more amino acids along the polypeptide chain from the N- or C-terminus. Non-limiting examples of NLSs include an NLS sequence derived from: the NLS of the SV40 virus large T-antigen, having the amino acid sequence PKKKRKV (SEQ ID NO: 2); the NLS from nucleoplasmin (e.g., the nucleoplasmin bipartite NLS with the sequence KRPAATKKAGQAKKKK (SEQ ID NO: 3)); the c-myc NLS having the amino acid sequence PAAKRVKLD (SEQ ID NO: 4) or RQRRNELKRSP (SEQ ID NO: 5); the hRNPA1 M9 NLS having the sequence NQSSNFGPMKGGNFGGRSSGPYGGGGQYFAKPRNQGGY (SEQ ID NO: 6); the sequence RMRIZFKNKGKDTAELRRRRVEVSVELRKAKKDEQILKRRNV (SEQ ID NO: 7) of the IBB domain from importin-alpha; the sequences VSRKRPRP (SEQ ID NO: 8) and PPKKARED (SEQ ID NO: 9) of the myoma T protein; the sequence PQPKKKPL (SEQ ID NO: 10) of human p53; the sequence SALIKKKKKMAP (SEQ ID NO: 11) of mouse c-abl IV; the sequences DRLRR (SEQ ID NO: 12) and PKQKKRK (SEQ ID NO: 13) of the influenza virus NS1; the sequence RKLKKKIKKL (SEQ ID NO: 14) of the Hepatitis virus delta antigen; the sequence REKKKFLKRR (SEQ ID NO: 15) of the mouse Mx1 protein; the sequence KRKGDEVDGVDEVAKKKSKK (SEQ ID NO: 16) of the human poly(ADP-ribose) polymerase; and the sequence RKCLQAGMNLEARKTKK (SEQ ID NO: 17) of the steroid hormone receptors (human) glucocorticoid. In general, the one or more NLSs are of sufficient strength to drive accumulation of the DNA/RNA-targeting Cas protein in a detectable amount in the nucleus of a eukaryotic cell. In general, strength of nuclear localization activity may derive from the number of NLSs in the nucleic acid-targeting effector protein, the particular NLS(s) used, or a combination of these factors. Detection of accumulation in the nucleus may be performed by any suitable technique. For example, a detectable marker may be fused to the nucleic acid-targeting protein, such that location within a cell may be visualized, such as in combination with a means for detecting the location of the nucleus (e.g., a stain specific for the nucleus such as DAPI). Cell nuclei may also be isolated from cells, the contents of which may then be analyzed by any suitable process for detecting protein, such as immunohistochemistry, Western blot, or enzyme activity assay. Accumulation in the nucleus may also be determined indirectly, such as by an assay for the effect of nucleic acid-targeting complex formation (e.g., assay for DNA or RNA cleavage or mutation at the target sequence, or assay for altered gene expression activity affected by DNA or RNA-targeting complex formation and/or DNA or RNA-targeting Cas protein activity), as compared to a control not exposed to the nucleic acid-targeting Cas protein or nucleic acid-targeting complex, or exposed to a nucleic acid-targeting Cas protein lacking the one or more NLSs. In preferred embodiments of the herein described Cpf1 effector protein complexes and systems the codon optimized Cpf1 effector proteins comprise an NLS attached to the C-terminal of the protein. In certain embodiments, other localization tags may be fused to the Cas protein, such as without limitation for localizing the Cas to particular sites in a cell, such as organelles, such mitochondria, plastids, chloroplast, vesicles, golgi, (nuclear or cellular) membranes, ribosomes, nucleolus, ER, cytoskeleton, vacuoles, centrosome, nucleosome, granules, centrioles, etc.

The invention also provides a non-naturally occurring or engineered composition, or one or more polynucleotides encoding components of said composition, or vector systems comprising one or more polynucleotides encoding components of said composition for use in a therapeutic method of treatment. The therapeutic method of treatment may comprise gene or genome editing, or gene therapy.

The nucleic acids-targeting systems, the vector systems, the vectors and the compositions described herein may be used in various nucleic acids-targeting applications, altering or modifying synthesis of a gene product, such as a protein, nucleic acids cleavage, nucleic acids editing, nucleic acids splicing; trafficking of target nucleic acids, tracing of target nucleic acids, isolation of target nucleic acids, visualization of target nucleic acids, etc.

In general, and throughout this specification, the term “vector” refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. Vectors include, but are not limited to, nucleic acid molecules that are single-stranded, double-stranded, or partially double-stranded; nucleic acid molecules that comprise one or more free ends, no free ends (e.g., circular); nucleic acid molecules that comprise DNA, RNA, or both; and other varieties of polynucleotides known in the art. One type of vector is a “plasmid,” which refers to a circular double stranded DNA loop into which additional DNA segments can be inserted, such as by standard molecular cloning techniques. Another type of vector is a viral vector, wherein virally-derived DNA or RNA sequences are present in the vector for packaging into a virus (e.g., retroviruses, replication defective retroviruses, adenoviruses, replication defective adenoviruses, and adeno-associated viruses). Viral vectors also include polynucleotides carried by a virus for transfection into a host cell. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) are integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, certain vectors are capable of directing the expression of genes to which they are operatively-linked. Such vectors are referred to herein as “expression vectors.” Vectors for and that result in expression in a eukaryotic cell can be referred to herein as “eukaryotic expression vectors.” Common expression vectors of utility in recombinant DNA techniques are often in the form of plasmids.

In certain embodiments, a vector system includes promoter-guide expression cassette in reverse order.

Recombinant expression vectors can comprise a nucleic acid of the invention in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed.

Advantageous vectors include lentiviruses and adeno-associated viruses, and types of such vectors can also be selected for targeting particular types of cells.

In some embodiments, one or more vectors driving expression of one or more elements of a nucleic acid-targeting system are introduced into a host cell such that expression of the elements of the nucleic acid-targeting system direct formation of a nucleic acid-targeting complex at one or more target sites. For example, a nucleic acid-targeting effector module and a nucleic acid-targeting guide RNA could each be operably linked to separate regulatory elements on separate vectors. RNA(s) of the nucleic acid-targeting system can be delivered to a transgenic nucleic acid-targeting effector module animal or mammal, e.g., an animal or mammal that constitutively or inducibly or conditionally expresses nucleic acid-targeting effector module; or an animal or mammal that is otherwise expressing nucleic acid-targeting effector modules or has cells containing nucleic acid-targeting effector modules, such as by way of prior administration thereto of a vector or vectors that code for and express in vivo nucleic acid-targeting effector modules. Alternatively, two or more of the elements expressed from the same or different regulatory elements, may be combined in a single vector, with one or more additional vectors providing any components of the nucleic acid-targeting system not included in the first vector. Nucleic acid-targeting system elements that are combined in a single vector may be arranged in any suitable orientation, such as one element located 5′ with respect to (“upstream” of) or 3′ with respect to (“downstream” of) a second element. The coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and oriented in the same or opposite direction. In some embodiments, a single promoter drives expression of a transcript encoding a nucleic acid-targeting effector module and the nucleic acid-targeting guide RNA, embedded within one or more intron sequences (e.g., each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the nucleic acid-targeting effector module and the nucleic acid-targeting guide RNA may be operably linked to and expressed from the same promoter.

In an aspect, the invention provides in a vector system comprising one or more vectors, wherein the one or more vectors comprises: a) a first regulatory element operably linked to a nucleotide sequence encoding the engineered CRISPR protein as defined herein; and optionally b) a second regulatory element operably linked to one or more nucleotide sequences encoding one or more nucleic acid molecules comprising a guide RNA comprising a guide sequence, a direct repeat sequence, optionally wherein components (a) and (b) are located on same or different vectors.

The invention also provides an engineered, non-naturally occurring Clustered Regularly Interspersed Short Palindromic Repeats (CRISPR)-CRISPR associated (Cas effector module) (CRISPR-Cas effector module) vector system comprising one or more vectors comprising: a) a first regulatory element operably linked to a nucleotide sequence encoding a non-naturally occurring CRISPR enzyme of any one of the inventive constructs herein; and b) a second regulatory element operably linked to one or more nucleotide sequences encoding one or more of the guide RNAs, the guide RNA comprising a guide sequence, a direct repeat sequence, wherein: components (a) and (b) are located on same or different vectors, the CRISPR complex is formed; the guide RNA targets the target polynucleotide loci and the enzyme alters the polynucleotide loci, and the enzyme in the CRISPR complex has reduced capability of modifying one or more off-target loci as compared to an unmodified enzyme and/or whereby the enzyme in the CRISPR complex has increased capability of modifying the one or more target loci as compared to an unmodified enzyme.

As used herein, a CRISPR-Cas effector module or CRISPR effector module includes, but is not limited to, Cas9, Cpf1, C2c2, Group 13b, and C2c1. In some embodiments, the CRISPR-Cas effector module may be engineered.

In such a system, component (II) may comprise a first regulatory element operably linked to a polynucleotide sequence which comprises the guide sequence, the direct repeat sequence, and wherein component (II) may comprise a second regulatory element operably linked to a polynucleotide sequence encoding the CRISPR enzyme. In such a system, where applicable the guide RNA may comprise a chimeric RNA.

In such a system, component (I) may comprise a first regulatory element operably linked to the guide sequence and the direct repeat sequence, and wherein component (II) may comprise a second regulatory element operably linked to a polynucleotide sequence encoding the CRISPR enzyme. Such a system may comprise more than one guide RNA, and each guide RNA has a different target whereby there is multiplexing. Components (a) and (b) may be on the same vector.

In any such systems comprising vectors, the one or more vectors may comprise one or more viral vectors, such as one or more retrovirus, lentivirus, adenovirus, adeno-associated virus or herpes simplex virus.

In any such systems comprising regulatory elements, at least one of said regulatory elements may comprise a tissue-specific promoter. The tissue-specific promoter may direct expression in a mammalian blood cell, in a mammalian liver cell or in a mammalian eye.

In any of the above-described compositions or systems the direct repeat sequence, may comprise one or more protein-interacting RNA aptamers. The one or more aptamers may be located in the tetraloop. The one or more aptamers may be capable of binding MS2 bacteriophage coat protein.

In any of the above-described compositions or systems the cell may be a eukaryotic cell or a prokaryotic cell; wherein the CRISPR complex is operable in the cell, and whereby the enzyme of the CRISPR complex has reduced capability of modifying one or more off-target loci of the cell as compared to an unmodified enzyme and/or whereby the enzyme in the CRISPR complex has increased capability of modifying the one or more target loci as compared to an unmodified enzyme.

The invention also provides a CRISPR complex of any of the above-described compositions or from any of the above-described systems.

The invention also provides a method of modifying a locus of interest in a cell comprising contacting the cell with any of the herein-described engineered CRISPR enzymes (e.g. engineered Cas effector module), compositions or any of the herein-described systems or vector systems, or wherein the cell comprises any of the herein-described CRISPR complexes present within the cell. In such methods the cell may be a prokaryotic or eukaryotic cell, preferably a eukaryotic cell. In such methods, an organism may comprise the cell. In such methods the organism may not be a human or other animal.

In certain embodiment, the invention also provides a non-naturally-occurring, engineered composition (e.g., engineered Cas9, Cpf1, C2c2, C2c1, Group 29/30, 13b, or any Cas protein which can fit into an AAV vector). Reference is made to FIGS. 19A, 19B, 19C, 19D, and 20A-F in U.S. Pat. No. 8,697,359 herein incorporated by reference to provide a list and guidance for other proteins which may also be used.

Any such method may be ex vivo or in vitro.

In certain embodiments, a nucleotide sequence encoding at least one of said guide RNA or Cpf1 effector module is operably connected in the cell with a regulatory element comprising a promoter of a gene of interest, whereby expression of at least one CRISPR-Cas effector module system component is driven by the promoter of the gene of interest. “operably connected” is intended to mean that the nucleotide sequence encoding the guide RNA and/or the Cas effector module is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence, as also referred to herein elsewhere. The term “regulatory element” is also described herein elsewhere. According to the invention, the regulatory element comprises a promoter of a gene of interest, such as preferably a promoter of an endogenous gene of interest. In certain embodiments, the promoter is at its endogenous genomic location. In such embodiments, the nucleic acid encoding the CRISPR and/or Cas effector module is under transcriptional control of the promoter of the gene of interest at its native genomic location. In certain other embodiments, the promoter is provided on a (separate) nucleic acid molecule, such as a vector or plasmid, or other extrachromosomal nucleic acid, i.e. the promoter is not provided at its native genomic location. In certain embodiments, the promoter is genomically integrated at a non-native genomic location.

The invention also provides a method of altering the expression of a genomic locus of interest in a mammalian cell comprising contacting the cell with the engineered CRISPR enzymes (e.g. engineered Cas effector module), compositions, systems or CRISPR complexes described herein and thereby delivering the CRISPR-Cas effector module (vector) and allowing the CRISPR-Cas effector module complex to form and bind to target, and determining if the expression of the genomic locus has been altered, such as increased or decreased expression, or modification of a gene product.

The invention further provides for a method of making mutations to a Cas effector module or a mutated or modified Cas effector module that is an ortholog of the CRISPR enzymes according to the invention as described herein, comprising ascertaining amino acid(s) in that ortholog may be in close proximity or may touch a nucleic acid molecule, e.g., DNA, RNA, gRNA, etc., and/or amino acid(s) analogous or corresponding to herein-identified amino acid(s) in CRISPR enzymes according to the invention as described herein for modification and/or mutation, and synthesizing or preparing or expressing the orthologue comprising, consisting of or consisting essentially of modification(s) and/or mutation(s) or mutating as herein-discussed, e.g., modifying, e.g., changing or mutating, a neutral amino acid to a charged, e.g., positively charged, amino acid, e.g., Alanine. The so modified ortholog can be used in CRISPR-Cas effector module systems; and nucleic acid molecule(s) expressing it may be used in vector systems that deliver molecules or encoding CRISPR-Cas effector module system components as herein-discussed.

In one aspect, the invention provides a kit comprising one or more of the components described herein. In some embodiments, the kit comprises a vector system and instructions for using the kit. In some embodiments, the vector system comprises (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide sequences downstream of the DR sequence, wherein when expressed, the guide sequence directs sequence-specific binding of a CRISPR-Cas effector module complex to a target sequence in a eukaryotic cell, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence, and (2) the DR sequence; and/or (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module comprising a nuclear localization sequence and advantageously this includes a split Cas effector module. In some embodiments, the kit comprises components (a) and (b) located on the same or different vectors of the system. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR-Cas effector module complex to a different target sequence in a eukaryotic cell.

In one aspect, the invention provides a method of modifying a target polynucleotide in a eukaryotic cell. In some embodiments, the method comprises allowing a CRISPR-Cas effector module complex to bind to the target polynucleotide to effect cleavage of said target polynucleotide thereby modifying the target polynucleotide, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with a guide sequence hybridized to a target sequence within said target polynucleotide, wherein said guide sequence is linked to a direct repeat sequence. In some embodiments, said cleavage comprises cleaving one or two strands at the location of the target sequence by said Cas effector module; this includes a split Cas effector module. In some embodiments, said cleavage results in decreased transcription of a target gene. In some embodiments, the method further comprises repairing said cleaved target polynucleotide by homologous recombination with an exogenous template polynucleotide, wherein said repair results in a mutation comprising an insertion, deletion, or substitution of one or more nucleotides of said target polynucleotide. In some embodiments, said mutation results in one or more amino acid changes in a protein expressed from a gene comprising the target sequence. In some embodiments, the method further comprises delivering one or more vectors to said eukaryotic cell, wherein the one or more vectors drive expression of one or more of: the Cas effector module, and the guide sequence linked to the DR sequence. In some embodiments, said vectors are delivered to the eukaryotic cell in a subject. In some embodiments, said modifying takes place in said eukaryotic cell in a cell culture. In some embodiments, the method further comprises isolating said eukaryotic cell from a subject prior to said modifying. In some embodiments, the method further comprises returning said eukaryotic cell and/or cells derived therefrom to said subject.

In one aspect, the invention provides a method of modifying expression of a polynucleotide in a eukaryotic cell. In some embodiments, the method comprises allowing a CRISPR-Cas effector module complex to bind to the polynucleotide such that said binding results in increased or decreased expression of said polynucleotide; wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with a guide sequence hybridized to a target sequence within said polynucleotide, wherein said guide sequence is linked to a direct repeat sequence; which may include a split Cas effector module. In some embodiments, the method further comprises delivering one or more vectors to said eukaryotic cells, wherein the one or more vectors drive expression of one or more of: the Cas effector module, and the guide sequence linked to the DR sequence.

In one aspect, the invention provides a method of generating a model eukaryotic cell comprising a mutated disease gene. In some embodiments, a disease gene is any gene associated an increase in the risk of having or developing a disease. In some embodiments, the method comprises (a) introducing one or more vectors into a eukaryotic cell, wherein the one or more vectors drive expression of one or more of: Cas effector module, and a guide sequence linked to a direct repeat sequence; and (b) allowing a CRISPR-Cas effector module complex to bind to a target polynucleotide to effect cleavage of the target polynucleotide within said disease gene, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence within the target polynucleotide, and (2) the DR sequence, thereby generating a model eukaryotic cell comprising a mutated disease gene; this includes a split Cas effector module. In some embodiments, said cleavage comprises cleaving one or two strands at the location of the target sequence by said Cas effector module. In a preferred embodiment, the strand break is a staggered cut with a 5′ overhang. In some embodiments, said cleavage results in decreased transcription of a target gene. In some embodiments, the method further comprises repairing said cleaved target polynucleotide by homologous recombination with an exogenous template polynucleotide, wherein said repair results in a mutation comprising an insertion, deletion, or substitution of one or more nucleotides of said target polynucleotide. In some embodiments, said mutation results in one or more amino acid changes in a protein expression from a gene comprising the target sequence.

In one aspect the invention provides for a method of selecting one or more cell(s) by introducing one or more mutations in a gene in the one or more cell (s), the method comprising: introducing one or more vectors into the cell (s), wherein the one or more vectors drive expression of one or more of: a Cas effector module, a guide sequence linked to a direct repeat sequence, and an editing template; wherein the editing template comprises the one or more mutations that abolish Cas effector module cleavage; allowing homologous recombination of the editing template with the target polynucleotide in the cell(s) to be selected; allowing a CRISPR-Cas effector module complex to bind to a target polynucleotide to effect cleavage of the target polynucleotide within said gene, wherein the CRISPR-Cas effector module complex comprises the Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence within the target polynucleotide, and (2) the direct repeat sequence, wherein binding of the Cas effector module CRISPR-Cas effector module complex to the target polynucleotide induces cell death, thereby allowing one or more cell(s) in which one or more mutations have been introduced to be selected; this includes a split Cas effector module. In another preferred embodiment of the invention the cell to be selected may be a eukaryotic cell. Aspects of the invention allow for selection of specific cells without requiring a selection marker or a two-step process that may include a counter-selection system.

Compositions comprising a Cas effector module, complex or system comprising multiple guide RNAs, preferably tandemly arranged, or the polynucleotide or vector encoding or comprising said Cas effector module, complex or system comprising multiple guide RNAs, preferably tandemly arranged, for use in the methods of treatment as defined herein elsewhere are also provided. A kit of parts may be provided including such compositions. Use of said composition in the manufacture of a medicament for such methods of treatment are also provided. Use of a Cas effector module CRISPR system in screening is also provided by the present invention, e.g., gain of function screens. Cells which are artificially forced to overexpress a gene are be able to down regulate the gene over time (re-establishing equilibrium) e.g. by negative feedback loops. By the time the screen starts the unregulated gene might be reduced again. Using an inducible Cas effector module activator allows one to induce transcription right before the screen and therefore minimizes the chance of false negative hits. Accordingly, by use of the instant invention in screening, e.g., gain of function screens, the chance of false negative results may be minimized.

In another aspect, the invention provides an engineered, non-naturally occurring vector system comprising one or more vectors comprising a first regulatory element operably linked to the multiple Cas effector module CRISPR system guide RNAs that each specifically target a DNA molecule encoding a gene product and a second regulatory element operably linked coding for a CRISPR protein. Both regulatory elements may be located on the same vector or on different vectors of the system. The multiple guide RNAs target the multiple DNA molecules encoding the multiple gene products in a cell and the CRISPR protein may cleave the multiple DNA molecules encoding the gene products (it may cleave one or both strands or have substantially no nuclease activity), whereby expression of the multiple gene products is altered; and, wherein the CRISPR protein and the multiple guide RNAs do not naturally occur together. In a preferred embodiment the CRISPR protein is a Cas effector module, optionally codon optimized for expression in a eukaryotic cell. In a preferred embodiment the eukaryotic cell is a mammalian cell, a plant cell or a yeast cell and in a more preferred embodiment the mammalian cell is a human cell. In a further embodiment of the invention, the expression of each of the multiple gene products is altered, preferably decreased.

In one aspect, the invention provides a vector system comprising one or more vectors. In some embodiments, the system comprises: (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide sequences up- or downstream (whichever applicable) of the direct repeat sequence, wherein when expressed, the one or more guide sequence(s) direct(s) sequence-specific binding of the CRISPR complex to the one or more target sequence(s) in a eukaryotic cell, wherein the CRISPR complex comprises a Cas effector module complexed with the one or more guide sequence(s) that is hybridized to the one or more target sequence(s); and (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module, preferably comprising at least one nuclear localization sequence and/or at least one NES; wherein components (a) and (b) are located on the same or different vectors of the system. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR complex to a different target sequence in a eukaryotic cell. In some embodiments, the CRISPR complex comprises one or more nuclear localization sequences and/or one or more NES of sufficient strength to drive accumulation of said CRISPR complex in a detectable amount in or out of the nucleus of a eukaryotic cell. In some embodiments, the first regulatory element is a polymerase III promoter. In some embodiments, the second regulatory element is a polymerase II promoter. In some embodiments, each of the guide sequences is at least 16, 17, 18, 19, 20, 25 nucleotides, or between 16-30, or between 16-25, or between 16-20 nucleotides in length.

Recombinant expression vectors can comprise the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed. Within a recombinant expression vector, “operably linked” is intended to mean that the nucleotide sequence of interest is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence (e.g., in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell).

In some embodiments, a host cell is transiently or non-transiently transfected with one or more vectors comprising the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein. In some embodiments, a cell is transfected as it naturally occurs in a subject. In some embodiments, a cell that is transfected is taken from a subject. In some embodiments, the cell is derived from cells taken from a subject, such as a cell line. A wide variety of cell lines for tissue culture are known in the art and exemplified herein elsewhere. Cell lines are available from a variety of sources known to those with skill in the art (see, e.g., the American Type Culture Collection (ATCC) (Manassas, Va.)). In some embodiments, a cell transfected with one or more vectors comprising the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein is used to establish a new cell line comprising one or more vector-derived sequences. In some embodiments, a cell transiently transfected with the components of a Cas effector module, system or complex for use in multiple targeting as described herein (such as by transient transfection of one or more vectors, or transfection with RNA), and modified through the activity of a Cas effector module, system or complex, is used to establish a new cell line comprising cells containing the modification but lacking any other exogenous sequence. In some embodiments, cells transiently or non-transiently transfected with one or more vectors comprising the polynucleotides encoding Cas effector module, system or complex for use in multiple targeting as defined herein, or cell lines derived from such cells are used in assessing one or more test compounds.

The term “regulatory element” is as defined herein elsewhere.

Advantageous vectors include lentiviruses and adeno-associated viruses, and types of such vectors can also be selected for targeting particular types of cells.

In one aspect, the invention provides a eukaryotic host cell comprising (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide RNA sequences up- or downstream (whichever applicable) of the direct repeat sequence, wherein when expressed, the guide sequence(s) direct(s) sequence-specific binding of the CRISPR complex to the respective target sequence(s) in a eukaryotic cell, wherein the CRISPR complex comprises a Cas effector module complexed with the one or more guide sequence(s) that is hybridized to the respective target sequence(s); and/or (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module comprising preferably at least one nuclear localization sequence and/or NES. In some embodiments, the host cell comprises components (a) and (b). In some embodiments, component (a), component (b), or components (a) and (b) are stably integrated into a genome of the host eukaryotic cell. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, and optionally separated by a direct repeat, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR complex to a different target sequence in a eukaryotic cell. In some embodiments, the Cas effector module comprises one or more nuclear localization sequences and/or nuclear export sequences or NES of sufficient strength to drive accumulation of said CRISPR enzyme in a detectable amount in and/or out of the nucleus of a eukaryotic cell.

Several aspects of the invention relate to vector systems comprising one or more vectors, or vectors as such. Vectors can be designed for expression of CRISPR transcripts (e.g. nucleic acid transcripts, proteins, or enzymes) in prokaryotic or eukaryotic cells. For example, CRISPR transcripts can be expressed in bacterial cells such as Escherichia coli , insect cells (using baculovirus expression vectors), yeast cells, or mammalian cells. Suitable host cells are discussed further in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Alternatively, the recombinant expression vector can be transcribed and translated in vitro, for example using T7 promoter regulatory sequences and T7 polymerase.

In certain aspects the invention involves vectors.

Recombinant expression vectors can comprise a nucleic acid of the invention in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed. Within a recombinant expression vector, “operably linked” is intended to mean that the nucleotide sequence of interest is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence (e.g. in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell). With regards to recombination and cloning methods, mention is made of U.S. patent application Ser. No. 10/815,730, published Sep. 2, 2004 as US 2004-0171156 A1, the contents of which are herein incorporated by reference in their entirety.

The vector(s) can include the regulatory element(s), e.g., promoter(s). The vector(s) can comprise Cas encoding sequences, and/or a single, but possibly also can comprise at least 3 or 8 or 16 or 32 or 48 or 50 guide RNA(s) (e.g., sgRNAs) encoding sequences, such as 1-2, 1-3, 1-4 1-5, 3-6, 3-7, 3-8, 3-9, 3-10, 3-8, 3-16, 3-30, 3-32, 3-48, 3-50 RNA(s) (e.g., sgRNAs). In a single vector there can be a promoter for each RNA (e.g., sgRNA), advantageously when there are up to about 16 RNA(s) (e.g., sgRNAs); and, when a single vector provides for more than 16 RNA(s) (e.g., sgRNAs), one or more promoter(s) can drive expression of more than one of the RNA(s) (e.g., sgRNAs), e.g., when there are 32 RNA(s) (e.g., sgRNAs), each promoter can drive expression of two RNA(s) (e.g., sgRNAs), and when there are 48 RNA(s) (e.g., sgRNAs), each promoter can drive expression of three RNA(s) (e.g., sgRNAs). By simple arithmetic and well established cloning protocols and the teachings in this disclosure one skilled in the art can readily practice the invention as to the RNA(s) (e.g., sgRNA(s) for a suitable exemplary vector such as AAV, and a suitable promoter such as the U6 promoter, e.g., U6-sgRNAs. For example, the packaging limit of AAV is ˜4.7 kb. The length of a single U6-sgRNA (plus restriction sites for cloning) is 361 bp. Therefore, the skilled person can readily fit about 12-16, e.g., 13 U6-sgRNA cassettes in a single vector. This can be assembled by any suitable means, such as a golden gate strategy used for TALE assembly (www.genome-engineering.org/taleffectors/). The skilled person can also use a tandem guide strategy to increase the number of U6-sgRNAs by approximately 1.5 times, e.g., to increase from 12-16, e.g., 13 to approximately 18-24, e.g., about 19 U6-sgRNAs. Therefore, one skilled in the art can readily reach approximately 18-24, e.g., about 19 promoter-RNAs, e.g., U6-sgRNAs in a single vector, e.g., an AAV vector. A further means for increasing the number of promoters and RNAs, e.g., sgRNA(s) in a vector is to use a single promoter (e.g., U6) to express an array of RNAs, e.g., sgRNAs separated by cleavable sequences. And an even further means for increasing the number of promoter-RNAs, e.g., sgRNAs in a vector, is to express an array of promoter-RNAs, e.g., sgRNAs separated by cleavable sequences in the intron of a coding sequence or gene; and, in this instance it is advantageous to use a polymerase II promoter, which can have increased expression and enable the transcription of long RNA in a tissue specific manner. (see, e.g., nar.oxfordjournals.org/content/34/7/e53.short, www.nature.com/mt/journal/v16/n9/abs/mt2008144a.html). In an advantageous embodiment, AAV may package U6 tandem sgRNA targeting up to about 50 genes. Accordingly, from the knowledge in the art and the teachings in this disclosure the skilled person can readily make and use vector(s), e.g., a single vector, expressing multiple RNAs or guides or sgRNAs under the control or operatively or functionally linked to one or more promoters—especially as to the numbers of RNAs or guides or sgRNAs discussed herein, without any undue experimentation.

The guide RNA(s), e.g., sgRNA(s) encoding sequences and/or Cas encoding sequences, can be functionally or operatively linked to regulatory element(s) and hence the regulatory element(s) drive expression. The promoter(s) can be constitutive promoter(s) and/or conditional promoter(s) and/or inducible promoter(s) and/or tissue specific promoter(s). The promoter can be selected from the group consisting of RNA polymerases, pol I, pol II, pol III, T7, U6, H1, retroviral Rous sarcoma virus (RSV) LTR promoter, the cytomegalovirus (CMV) promoter, the SV40 promoter, the dihydrofolate reductase promoter, the β-actin promoter, the phosphoglycerol kinase (PGK) promoter, and the EF1α promoter. An advantageous promoter is the promoter is U6.

Aspects of the invention relate to bicistronic vectors for guide RNA and (optionally modified or mutated) Cas effector modules. Bicistronic expression vectors for guide RNA and (optionally modified or mutated) CRISPR enzymes are preferred. In general and particularly in this embodiment (optionally modified or mutated) CRISPR enzymes are preferably driven by the CBh promoter. The RNA may preferably be driven by a Pol III promoter, such as a U6 promoter. Ideally the two are combined.

In some embodiments, a loop in the guide RNA is provided. This may be a stem loop or a tetra loop. The loop is preferably GAAA, but it is not limited to this sequence or indeed to being only 4 bp in length. Indeed, preferred loop forming sequences for use in hairpin structures are four nucleotides in length, and most preferably have the sequence GAAA. However, longer or shorter loop sequences may be used, as may alternative sequences. The sequences preferably include a nucleotide triplet (for example, AAA), and an additional nucleotide (for example C or G). Examples of loop forming sequences include CAAA and AAAG.

The term “regulatory element” is intended to include promoters, enhancers, internal ribosomal entry sites (IRES), and other expression control elements (e.g. transcription termination signals, such as polyadenylation signals and poly-U sequences).

Vectors can be designed for expression of CRISPR transcripts (e.g. nucleic acid transcripts, proteins, or enzymes) in prokaryotic or eukaryotic cells. For example, CRISPR transcripts can be expressed in bacterial cells such as Escherichia coli , insect cells (using baculovirus expression vectors), yeast cells, or mammalian cells. Suitable host cells are discussed further in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Alternatively, the recombinant expression vector can be transcribed and translated in vitro, for example using T7 promoter regulatory sequences and T7 polymerase.

Vectors may be introduced and propagated in a prokaryote or prokaryotic cell. In some embodiments, a prokaryote is used to amplify copies of a vector to be introduced into a eukaryotic cell or as an intermediate vector in the production of a vector to be introduced into a eukaryotic cell (e.g. amplifying a plasmid as part of a viral vector packaging system). In some embodiments, a prokaryote is used to amplify copies of a vector and express one or more nucleic acids, such as to provide a source of one or more proteins for delivery to a host cell or host organism. Expression of proteins in prokaryotes is most often carried out in Escherichia coli with vectors containing constitutive or inducible promoters directing the expression of either fusion or non-fusion proteins. Fusion vectors add a number of amino acids to a protein encoded therein, such as to the amino terminus of the recombinant protein. Such fusion vectors may serve one or more purposes, such as: (i) to increase expression of recombinant protein; (ii) to increase the solubility of the recombinant protein; and (iii) to aid in the purification of the recombinant protein by acting as a ligand in affinity purification. Often, in fusion expression vectors, a proteolytic cleavage site is introduced at the junction of the fusion moiety and the recombinant protein to enable separation of the recombinant protein from the fusion moiety subsequent to purification of the fusion protein. Such enzymes, and their cognate recognition sequences, include Factor Xa, thrombin and enterokinase. Example fusion expression vectors include pGEX (Pharmacia Biotech Inc; Smith and Johnson, 1988. Gene 67: 31-40), pMAL (New England Biolabs, Beverly, Mass.) and pRIT5 (Pharmacia, Piscataway, N.J.) that fuse glutathione S-transferase (GST), maltose E binding protein, or protein A, respectively, to the target recombinant protein. Examples of suitable inducible non-fusion E. coli expression vectors include pTrc (Amrann et al., (1988) Gene 69:301-315) and pET 11d (Studier et al., GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990) 60-89). In some embodiments, a vector is a yeast expression vector. Examples of vectors for expression in yeast Saccharomyces cerevisiae include pYepSec1 (Baldari, et al., 1987. EMBO J. 6: 229-234), pMFa (Kuijan and Herskowitz, 1982. Cell 30: 933-943), pJRY88 (Schultz et al., 1987. Gene 54: 113-123), pYES2 (Invitrogen Corporation, San Diego, Calif.), and picZ (InVitrogen Corp, San Diego, Calif.). In some embodiments, a vector drives protein expression in insect cells using baculovirus expression vectors. Baculovirus vectors available for expression of proteins in cultured insect cells (e.g., SF9 cells) include the pAc series (Smith, et al., 1983. Mol. Cell. Biol. 3: 2156-2165) and the pVL series (Lucklow and Summers, 1989. Virology 170: 31-39).

In some embodiments, a vector is capable of driving expression of one or more sequences in mammalian cells using a mammalian expression vector. Examples of mammalian expression vectors include pCDM8 (Seed, 1987. Nature 329: 840) and pMT2PC (Kaufman, et al., 1987. EMBO J. 6: 187-195). When used in mammalian cells, the expression vector's control functions are typically provided by one or more regulatory elements. For example, commonly used promoters are derived from polyoma, adenovirus 2, cytomegalovirus, simian virus 40, and others disclosed herein and known in the art. For other suitable expression systems for both prokaryotic and eukaryotic cells see, e.g., Chapters 16 and 17 of Sambrook, et al., MOLECULAR CLONING: A LABORATORY MANUAL. 2nd ed., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989.

In some embodiments, the recombinant mammalian expression vector is capable of directing expression of the nucleic acid preferentially in a particular cell type (e.g., tissue-specific regulatory elements are used to express the nucleic acid). Tissue-specific regulatory elements are known in the art. Non-limiting examples of suitable tissue-specific promoters include the albumin promoter (liver-specific; Pinkert, et al., 1987. Genes Dev. 1: 268-277), lymphoid-specific promoters (Calame and Eaton, 1988. Adv. Immunol. 43: 235-275), in particular promoters of T cell receptors (Winoto and Baltimore, 1989. EMBO J. 8: 729-733) and immunoglobulins (Baneiji, et al., 1983. Cell 33: 729-740; Queen and Baltimore, 1983. Cell 33: 741-748), neuron-specific promoters (e.g., the neurofilament promoter; Byrne and Ruddle, 1989. Proc. Natl. Acad. Sci. USA 86: 5473-5477), pancreas-specific promoters (Edlund, et al., 1985. Science 230: 912-916), and mammary gland-specific promoters (e.g., milk whey promoter; U.S. Pat. No. 4,873,316 and European Application Publication No. 264,166). Developmentally-regulated promoters are also encompassed, e.g., the murine hox promoters (Kessel and Gruss, 1990. Science 249: 374-379) and the a-fetoprotein promoter (Campes and Tilghman, 1989. Genes Dev. 3: 537-546). With regards to these prokaryotic and eukaryotic vectors, mention is made of U.S. Pat. No. 6,750,059, the contents of which are incorporated by reference herein in their entirety. Other embodiments of the invention may relate to the use of viral vectors, with regards to which mention is made of U.S. patent application Ser. No. 13/092,085, the contents of which are incorporated by reference herein in their entirety. Tissue-specific regulatory elements are known in the art and in this regard, mention is made of U.S. Pat. No. 7,776,321, the contents of which are incorporated by reference herein in their entirety. In some embodiments, a regulatory element is operably linked to one or more elements of a CRISPR system so as to drive expression of the one or more elements of the CRISPR system. In general, CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), also known as SPIDRs (SPacer Interspersed Direct Repeats), constitute a family of DNA loci that are usually specific to a particular bacterial species. The CRISPR locus comprises a distinct class of interspersed short sequence repeats (SSRs) that were recognized in E. coli (Ishino et al., J. Bacteriol., 169:5429-5433 [1987]; and Nakata et al., J. Bacteriol., 171:3553-3556 [1989]), and associated genes. Similar interspersed SSRs have been identified in Haloferax mediterranei, Streptococcus pyogenes, Anabaena , and Mycobacterium tuberculosis (See, Groenen et al., Mol. Microbiol., 10:1057-1065 [1993]; Hoe et al., Emerg. Infect. Dis., 5:254-263 [1999]; Masepohl et al., Biochim. Biophys. Acta 1307:26-30 [1996]; and Mojica et al., Mol. Microbiol., 17:85-93 [1995]). The CRISPR loci typically differ from other SSRs by the structure of the repeats, which have been termed short regularly spaced repeats (SRSRs) (Janssen et al., OMICS J. Integ. Biol., 6:23-33 [2002]; and Mojica et al., Mol. Microbiol., 36:244-246 [2000]). In general, the repeats are short elements that occur in clusters that are regularly spaced by unique intervening sequences with a substantially constant length (Mojica et al., [2000], supra). Although the repeat sequences are highly conserved between strains, the number of interspersed repeats and the sequences of the spacer regions typically differ from strain to strain (van Embden et al., J. Bacteriol., 182:2393-2401 [2000]). CRISPR loci have been identified in more than 40 prokaryotes (See e.g., Jansen et al., Mol. Microbiol., 43:1565-1575 [2002]; and Mojica et al., [2005]) including, but not limited to Aeropyrum, Pyrobaculum, Sulfolobus, Archaeoglobus, Haloarcula, Methanobacterium, Methanococcus, Methanosarcina, Methanopyrus, Pyrococcus, Picrophilus, Thermoplasma, Corynebacterium, Mycobacterium, Streptomyces, Aquifex, Porphyromonas, Chlorobium, Thermus, Bacillus, Listeria, Staphylococcus, Clostridium, Thermoanaerobacter, Mycoplasma, Fusobacterium, Azoarcus, Chromobacterium, Neisseria, Nitrosomonas, Desulfovibrio, Geobacter, Myxococcus, Campylobacter, Wolinella, Acinetobacter, Erwinia, Escherichia, Legionella, Methylococcus, Pasteurella, Photobacterium, Salmonella, Xanthomonas, Yersinia, Treponema , and Thermotoga.

Typically, in the context of an endogenous nucleic acid-targeting system, formation of a nucleic acid-targeting complex (comprising a guide RNA hybridized to a target sequence and complexed with one or more nucleic acid-targeting effector modules) results in cleavage of one or both RNA strands in or near (e.g. within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from) the target sequence. In some embodiments, one or more vectors driving expression of one or more elements of a nucleic acid-targeting system are introduced into a host cell such that expression of the elements of the nucleic acid-targeting system direct formation of a nucleic acid-targeting complex at one or more target sites. For example, a nucleic acid-targeting effector module and a guide RNA could each be operably linked to separate regulatory elements on separate vectors. Alternatively, two or more of the elements expressed from the same or different regulatory elements, may be combined in a single vector, with one or more additional vectors providing any components of the nucleic acid-targeting system not included in the first vector. Nucleic acid-targeting system elements that are combined in a single vector may be arranged in any suitable orientation, such as one element located 5′ with respect to (“upstream” of) or 3′ with respect to (“downstream” of) a second element. The coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and oriented in the same or opposite direction. In some embodiments, a single promoter drives expression of a transcript encoding a nucleic acid-targeting effector module and a guide RNA embedded within one or more intron sequences (e.g. each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the nucleic acid-targeting effector module and guide RNA are operably linked to and expressed from the same promoter.

In certain embodiments, a nucleotide sequence encoding at least one of said guide RNA or Cpf1 effector module is operably connected in the cell with a regulatory element comprising a promoter of a gene of interest, whereby expression of at least one CRISPR-Cas effector module system component is driven by the promoter of the gene of interest. “operably connected” is intended to mean that the nucleotide sequence encoding the guide RNA and/or the Cas effector module is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence, as also referred to herein elsewhere. The term “regulatory element” is also described herein elsewhere. According to the invention, the regulatory element comprises a promoter of a gene of interest, such as preferably a promoter of an endogenous gene of interest. In certain embodiments, the promoter is at its endogenous genomic location. In such embodiments, the nucleic acid encoding the CRISPR and/or Cas effector module is under transcriptional control of the promoter of the gene of interest at its native genomic location. In certain other embodiments, the promoter is provided on a (separate) nucleic acid molecule, such as a vector or plasmid, or other extrachromosomal nucleic acid, i.e. the promoter is not provided at its native genomic location. In certain embodiments, the promoter is genomically integrated at a non-native genomic location.

The invention also provides a method of altering the expression of a genomic locus of interest in a mammalian cell comprising contacting the cell with the engineered CRISPR enzymes (e.g. engineered Cas effector module), compositions, systems or CRISPR complexes described herein and thereby delivering the CRISPR-Cas effector module (vector) and allowing the CRISPR-Cas effector module complex to form and bind to target, and determining if the expression of the genomic locus has been altered, such as increased or decreased expression, or modification of a gene product.

The invention further provides for a method of making mutations to a Cas effector module or a mutated or modified Cas effector module that is an ortholog of the CRISPR enzymes according to the invention as described herein, comprising ascertaining amino acid(s) in that ortholog may be in close proximity or may touch a nucleic acid molecule, e.g., DNA, RNA, gRNA, etc., and/or amino acid(s) analogous or corresponding to herein-identified amino acid(s) in CRISPR enzymes according to the invention as described herein for modification and/or mutation, and synthesizing or preparing or expressing the orthologue comprising, consisting of or consisting essentially of modification(s) and/or mutation(s) or mutating as herein-discussed, e.g., modifying, e.g., changing or mutating, a neutral amino acid to a charged, e.g., positively charged, amino acid, e.g., Alanine. The so modified ortholog can be used in CRISPR-Cas effector module systems; and nucleic acid molecule(s) expressing it may be used in vector systems that deliver molecules or encoding CRISPR-Cas effector module system components as herein-discussed.

In one aspect, the invention provides a kit comprising one or more of the components described herein. In some embodiments, the kit comprises a vector system and instructions for using the kit. In some embodiments, the vector system comprises (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide sequences downstream of the DR sequence, wherein when expressed, the guide sequence directs sequence-specific binding of a CRISPR-Cas effector module complex to a target sequence in a eukaryotic cell, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence, and (2) the DR sequence; and/or (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module comprising a nuclear localization sequence and advantageously this includes a split Cas effector module. In some embodiments, the kit comprises components (a) and (b) located on the same or different vectors of the system. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR-Cas effector module complex to a different target sequence in a eukaryotic cell.

In one aspect, the invention provides a method of modifying a target polynucleotide in a eukaryotic cell. In some embodiments, the method comprises allowing a CRISPR-Cas effector module complex to bind to the target polynucleotide to effect cleavage of said target polynucleotide thereby modifying the target polynucleotide, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with a guide sequence hybridized to a target sequence within said target polynucleotide, wherein said guide sequence is linked to a direct repeat sequence. In some embodiments, said cleavage comprises cleaving one or two strands at the location of the target sequence by said Cas effector module; this includes a split Cas effector module. In some embodiments, said cleavage results in decreased transcription of a target gene. In some embodiments, the method further comprises repairing said cleaved target polynucleotide by homologous recombination with an exogenous template polynucleotide, wherein said repair results in a mutation comprising an insertion, deletion, or substitution of one or more nucleotides of said target polynucleotide. In some embodiments, said mutation results in one or more amino acid changes in a protein expressed from a gene comprising the target sequence. In some embodiments, the method further comprises delivering one or more vectors to said eukaryotic cell, wherein the one or more vectors drive expression of one or more of: the Cas effector module, and the guide sequence linked to the DR sequence. In some embodiments, said vectors are delivered to the eukaryotic cell in a subject. In some embodiments, said modifying takes place in said eukaryotic cell in a cell culture. In some embodiments, the method further comprises isolating said eukaryotic cell from a subject prior to said modifying. In some embodiments, the method further comprises returning said eukaryotic cell and/or cells derived therefrom to said subject.

In one aspect, the invention provides a method of modifying expression of a polynucleotide in a eukaryotic cell. In some embodiments, the method comprises allowing a CRISPR-Cas effector module complex to bind to the polynucleotide such that said binding results in increased or decreased expression of said polynucleotide; wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with a guide sequence hybridized to a target sequence within said polynucleotide, wherein said guide sequence is linked to a direct repeat sequence; which may include a split Cas effector module. In some embodiments, the method further comprises delivering one or more vectors to said eukaryotic cells, wherein the one or more vectors drive expression of one or more of: the Cas effector module, and the guide sequence linked to the DR sequence.

In one aspect, the invention provides a method of generating a model eukaryotic cell comprising a mutated disease gene. In some embodiments, a disease gene is any gene associated an increase in the risk of having or developing a disease. In some embodiments, the method comprises (a) introducing one or more vectors into a eukaryotic cell, wherein the one or more vectors drive expression of one or more of: Cas effector module, and a guide sequence linked to a direct repeat sequence; and (b) allowing a CRISPR-Cas effector module complex to bind to a target polynucleotide to effect cleavage of the target polynucleotide within said disease gene, wherein the CRISPR-Cas effector module complex comprises a Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence within the target polynucleotide, and (2) the DR sequence, thereby generating a model eukaryotic cell comprising a mutated disease gene; this includes a split Cas effector module. In some embodiments, said cleavage comprises cleaving one or two strands at the location of the target sequence by said Cas effector module. In a preferred embodiment, the strand break is a staggered cut with a 5′ overhang. In some embodiments, said cleavage results in decreased transcription of a target gene. In some embodiments, the method further comprises repairing said cleaved target polynucleotide by homologous recombination with an exogenous template polynucleotide, wherein said repair results in a mutation comprising an insertion, deletion, or substitution of one or more nucleotides of said target polynucleotide. In some embodiments, said mutation results in one or more amino acid changes in a protein expression from a gene comprising the target sequence.

In one aspect the invention provides for a method of selecting one or more cell(s) by introducing one or more mutations in a gene in the one or more cell (s), the method comprising: introducing one or more vectors into the cell (s), wherein the one or more vectors drive expression of one or more of: a Cas effector module, a guide sequence linked to a direct repeat sequence, and an editing template; wherein the editing template comprises the one or more mutations that abolish Cas effector module cleavage; allowing homologous recombination of the editing template with the target polynucleotide in the cell(s) to be selected; allowing a CRISPR-Cas effector module complex to bind to a target polynucleotide to effect cleavage of the target polynucleotide within said gene, wherein the CRISPR-Cas effector module complex comprises the Cas effector module complexed with (1) the guide sequence that is hybridized to the target sequence within the target polynucleotide, and (2) the direct repeat sequence, wherein binding of the Cas effector module CRISPR-Cas effector module complex to the target polynucleotide induces cell death, thereby allowing one or more cell(s) in which one or more mutations have been introduced to be selected; this includes a split Cas effector module. In another preferred embodiment of the invention the cell to be selected may be a eukaryotic cell. Aspects of the invention allow for selection of specific cells without requiring a selection marker or a two-step process that may include a counter-selection system.

Compositions comprising a Cas effector module, complex or system comprising multiple guide RNAs, preferably tandemly arranged, or the polynucleotide or vector encoding or comprising said Cas effector module, complex or system comprising multiple guide RNAs, preferably tandemly arranged, for use in the methods of treatment as defined herein elsewhere are also provided. A kit of parts may be provided including such compositions. Use of said composition in the manufacture of a medicament for such methods of treatment are also provided. Use of a Cas effector module CRISPR system in screening is also provided by the present invention, e.g., gain of function screens. Cells which are artificially forced to overexpress a gene are be able to down regulate the gene over time (re-establishing equilibrium) e.g. by negative feedback loops. By the time the screen starts the unregulated gene might be reduced again. Using an inducible Cas effector module activator allows one to induce transcription right before the screen and therefore minimizes the chance of false negative hits. Accordingly, by use of the instant invention in screening, e.g., gain of function screens, the chance of false negative results may be minimized.

In another aspect, the invention provides an engineered, non-naturally occurring vector system comprising one or more vectors comprising a first regulatory element operably linked to the multiple Cas effector module CRISPR system guide RNAs that each specifically target a DNA molecule encoding a gene product and a second regulatory element operably linked coding for a CRISPR protein. Both regulatory elements may be located on the same vector or on different vectors of the system. The multiple guide RNAs target the multiple DNA molecules encoding the multiple gene products in a cell and the CRISPR protein may cleave the multiple DNA molecules encoding the gene products (it may cleave one or both strands or have substantially no nuclease activity), whereby expression of the multiple gene products is altered; and, wherein the CRISPR protein and the multiple guide RNAs do not naturally occur together. In a preferred embodiment the CRISPR protein is a Cas effector module, optionally codon optimized for expression in a eukaryotic cell. In a preferred embodiment the eukaryotic cell is a mammalian cell, a plant cell or a yeast cell and in a more preferred embodiment the mammalian cell is a human cell. In a further embodiment of the invention, the expression of each of the multiple gene products is altered, preferably decreased.

In one aspect, the invention provides a vector system comprising one or more vectors. In some embodiments, the system comprises: (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide sequences up- or downstream (whichever applicable) of the direct repeat sequence, wherein when expressed, the one or more guide sequence(s) direct(s) sequence-specific binding of the CRISPR complex to the one or more target sequence(s) in a eukaryotic cell, wherein the CRISPR complex comprises a Cas effector module complexed with the one or more guide sequence(s) that is hybridized to the one or more target sequence(s); and (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module, preferably comprising at least one nuclear localization sequence and/or at least one NES; wherein components (a) and (b) are located on the same or different vectors of the system. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR complex to a different target sequence in a eukaryotic cell. In some embodiments, the CRISPR complex comprises one or more nuclear localization sequences and/or one or more NES of sufficient strength to drive accumulation of said CRISPR complex in a detectable amount in or out of the nucleus of a eukaryotic cell. In some embodiments, the first regulatory element is a polymerase III promoter. In some embodiments, the second regulatory element is a polymerase II promoter. In some embodiments, each of the guide sequences is at least 16, 17, 18, 19, 20, 25 nucleotides, or between 16-30, or between 16-25, or between 16-20 nucleotides in length.

Recombinant expression vectors can comprise the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed. Within a recombinant expression vector, “operably linked” is intended to mean that the nucleotide sequence of interest is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence (e.g., in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell).

In some embodiments, a host cell is transiently or non-transiently transfected with one or more vectors comprising the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein. In some embodiments, a cell is transfected as it naturally occurs in a subject. In some embodiments, a cell that is transfected is taken from a subject. In some embodiments, the cell is derived from cells taken from a subject, such as a cell line. A wide variety of cell lines for tissue culture are known in the art and exemplified herein elsewhere. Cell lines are available from a variety of sources known to those with skill in the art (see, e.g., the American Type Culture Collection (ATCC) (Manassas, Va.)). In some embodiments, a cell transfected with one or more vectors comprising the polynucleotides encoding the Cas effector module, system or complex for use in multiple targeting as defined herein is used to establish a new cell line comprising one or more vector-derived sequences. In some embodiments, a cell transiently transfected with the components of a Cas effector module, system or complex for use in multiple targeting as described herein (such as by transient transfection of one or more vectors, or transfection with RNA), and modified through the activity of a Cas effector module, system or complex, is used to establish a new cell line comprising cells containing the modification but lacking any other exogenous sequence. In some embodiments, cells transiently or non-transiently transfected with one or more vectors comprising the polynucleotides encoding Cas effector module, system or complex for use in multiple targeting as defined herein, or cell lines derived from such cells are used in assessing one or more test compounds.

The term “regulatory element” is as defined herein elsewhere.

Advantageous vectors include lentiviruses and adeno-associated viruses, and types of such vectors can also be selected for targeting particular types of cells.

In one aspect, the invention provides a eukaryotic host cell comprising (a) a first regulatory element operably linked to a direct repeat sequence and one or more insertion sites for inserting one or more guide RNA sequences up- or downstream (whichever applicable) of the direct repeat sequence, wherein when expressed, the guide sequence(s) direct(s) sequence-specific binding of the CRISPR complex to the respective target sequence(s) in a eukaryotic cell, wherein the CRISPR complex comprises a Cas effector module complexed with the one or more guide sequence(s) that is hybridized to the respective target sequence(s); and/or (b) a second regulatory element operably linked to an enzyme-coding sequence encoding said Cas effector module comprising preferably at least one nuclear localization sequence and/or NES. In some embodiments, the host cell comprises components (a) and (b). In some embodiments, component (a), component (b), or components (a) and (b) are stably integrated into a genome of the host eukaryotic cell. In some embodiments, component (a) further comprises two or more guide sequences operably linked to the first regulatory element, and optionally separated by a direct repeat, wherein when expressed, each of the two or more guide sequences direct sequence specific binding of a CRISPR complex to a different target sequence in a eukaryotic cell. In some embodiments, the Cas effector module comprises one or more nuclear localization sequences and/or nuclear export sequences or NES of sufficient strength to drive accumulation of said CRISPR enzyme in a detectable amount in and/or out of the nucleus of a eukaryotic cell.

Several aspects of the invention relate to vector systems comprising one or more vectors, or vectors as such. Vectors can be designed for expression of CRISPR transcripts (e.g. nucleic acid transcripts, proteins, or enzymes) in prokaryotic or eukaryotic cells. For example, CRISPR transcripts can be expressed in bacterial cells such as Escherichia coli , insect cells (using baculovirus expression vectors), yeast cells, or mammalian cells. Suitable host cells are discussed further in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Alternatively, the recombinant expression vector can be transcribed and translated in vitro, for example using T7 promoter regulatory sequences and T7 polymerase.

In certain aspects the invention involves vectors. A used herein, a “vector” is a tool that allows or facilitates the transfer of an entity from one environment to another. It is a replicon, such as a plasmid, phage, or cosmid, into which another DNA segment may be inserted so as to bring about the replication of the inserted segment. Generally, a vector is capable of replication when associated with the proper control elements. In general, the term “vector” refers to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. Vectors include, but are not limited to, nucleic acid molecules that are single-stranded, double-stranded, or partially double-stranded; nucleic acid molecules that comprise one or more free ends, no free ends (e.g. circular); nucleic acid molecules that comprise DNA, RNA, or both; and other varieties of polynucleotides known in the art. One type of vector is a “plasmid,” which refers to a circular double stranded DNA loop into which additional DNA segments can be inserted, such as by standard molecular cloning techniques. Another type of vector is a viral vector, wherein virally-derived DNA or RNA sequences are present in the vector for packaging into a virus (e.g. retroviruses, replication defective retroviruses, adenoviruses, replication defective adenoviruses, and adeno-associated viruses (AAVs)). Viral vectors also include polynucleotides carried by a virus for transfection into a host cell. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g. bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) are integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, certain vectors are capable of directing the expression of genes to which they are operatively-linked. Such vectors are referred to herein as “expression vectors.” Common expression vectors of utility in recombinant DNA techniques are often in the form of plasmids.

Recombinant expression vectors can comprise a nucleic acid of the invention in a form suitable for expression of the nucleic acid in a host cell, which means that the recombinant expression vectors include one or more regulatory elements, which may be selected on the basis of the host cells to be used for expression, that is operatively-linked to the nucleic acid sequence to be expressed. Within a recombinant expression vector, “operably linked” is intended to mean that the nucleotide sequence of interest is linked to the regulatory element(s) in a manner that allows for expression of the nucleotide sequence (e.g. in an in vitro transcription/translation system or in a host cell when the vector is introduced into the host cell). With regards to recombination and cloning methods, mention is made of U.S. patent application Ser. No. 10/815,730, published Sep. 2, 2004 as US 2004-0171156 A1, the contents of which are herein incorporated by reference in their entirety.

The vector(s) can include the regulatory element(s), e.g., promoter(s). The vector(s) can comprise Cas encoding sequences, and/or a single, but possibly also can comprise at least 3 or 8 or 16 or 32 or 48 or 50 guide RNA(s) (e.g., sgRNAs) encoding sequences, such as 1-2, 1-3, 1-4 1-5, 3-6, 3-7, 3-8, 3-9, 3-10, 3-8, 3-16, 3-30, 3-32, 3-48, 3-50 RNA(s) (e.g., sgRNAs). In a single vector there can be a promoter for each RNA (e.g., sgRNA), advantageously when there are up to about 16 RNA(s) (e.g., sgRNAs); and, when a single vector provides for more than 16 RNA(s) (e.g., sgRNAs), one or more promoter(s) can drive expression of more than one of the RNA(s) (e.g., sgRNAs), e.g., when there are 32 RNA(s) (e.g., sgRNAs), each promoter can drive expression of two RNA(s) (e.g., sgRNAs), and when there are 48 RNA(s) (e.g., sgRNAs), each promoter can drive expression of three RNA(s) (e.g., sgRNAs). By simple arithmetic and well established cloning protocols and the teachings in this disclosure one skilled in the art can readily practice the invention as to the RNA(s) (e.g., sgRNA(s) for a suitable exemplary vector such as AAV, and a suitable promoter such as the U6 promoter, e.g., U6-sgRNAs. For example, the packaging limit of AAV is ˜4.7 kb. The length of a single U6-sgRNA (plus restriction sites for cloning) is 361 bp. Therefore, the skilled person can readily fit about 12-16, e.g., 13 U6-sgRNA cassettes in a single vector. This can be assembled by any suitable means, such as a golden gate strategy used for TALE assembly (www.genome-engineering.org/taleffectors/). The skilled person can also use a tandem guide strategy to increase the number of U6-sgRNAs by approximately 1.5 times, e.g., to increase from 12-16, e.g., 13 to approximately 18-24, e.g., about 19 U6-sgRNAs. Therefore, one skilled in the art can readily reach approximately 18-24, e.g., about 19 promoter-RNAs, e.g., U6-sgRNAs in a single vector, e.g., an AAV vector. A further means for increasing the number of promoters and RNAs, e.g., sgRNA(s) in a vector is to use a single promoter (e.g., U6) to express an array of RNAs, e.g., sgRNAs separated by cleavable sequences. And an even further means for increasing the number of promoter-RNAs, e.g., sgRNAs in a vector, is to express an array of promoter-RNAs, e.g., sgRNAs separated by cleavable sequences in the intron of a coding sequence or gene; and, in this instance it is advantageous to use a polymerase II promoter, which can have increased expression and enable the transcription of long RNA in a tissue specific manner. (see, e.g., nar.oxfordjournals.org/content/34/7/e53.short, www.nature.com/mt/journal/v16/n9/abs/mt2008144a.html). In an advantageous embodiment, AAV may package U6 tandem sgRNA targeting up to about 50 genes. Accordingly, from the knowledge in the art and the teachings in this disclosure the skilled person can readily make and use vector(s), e.g., a single vector, expressing multiple RNAs or guides or sgRNAs under the control or operatively or functionally linked to one or more promoters—especially as to the numbers of RNAs or guides or sgRNAs discussed herein, without any undue experimentation.

The guide RNA(s), e.g., sgRNA(s) encoding sequences and/or Cas encoding sequences, can be functionally or operatively linked to regulatory element(s) and hence the regulatory element(s) drive expression. The promoter(s) can be constitutive promoter(s) and/or conditional promoter(s) and/or inducible promoter(s) and/or tissue specific promoter(s). The promoter can be selected from the group consisting of RNA polymerases, pol I, pol II, pol III, T7, U6, H1, retroviral Rous sarcoma virus (RSV) LTR promoter, the cytomegalovirus (CMV) promoter, the SV40 promoter, the dihydrofolate reductase promoter, the β-actin promoter, the phosphoglycerol kinase (PGK) promoter, and the EF1α promoter. An advantageous promoter is the promoter is U6.

Aspects of the invention relate to bicistronic vectors for guide RNA and (optionally modified or mutated) Cas effector modules. Bicistronic expression vectors for guide RNA and (optionally modified or mutated) CRISPR enzymes are preferred. In general and particularly in this embodiment (optionally modified or mutated) CRISPR enzymes are preferably driven by the CBh promoter. The RNA may preferably be driven by a Pol III promoter, such as a U6 promoter. Ideally the two are combined.

In some embodiments, a loop in the guide RNA is provided. This may be a stem loop or a tetra loop. The loop is preferably GAAA, but it is not limited to this sequence or indeed to being only 4 bp in length. Indeed, preferred loop forming sequences for use in hairpin structures are four nucleotides in length, and most preferably have the sequence GAAA. However, longer or shorter loop sequences may be used, as may alternative sequences. The sequences preferably include a nucleotide triplet (for example, AAA), and an additional nucleotide (for example C or G). Examples of loop forming sequences include CAAA and AAAG.

The term “regulatory element” is intended to include promoters, enhancers, internal ribosomal entry sites (IRES), and other expression control elements (e.g. transcription termination signals, such as polyadenylation signals and poly-U sequences). Such regulatory elements are described, for example, in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Regulatory elements include those that direct constitutive expression of a nucleotide sequence in many types of host cell and those that direct expression of the nucleotide sequence only in certain host cells (e.g., tissue-specific regulatory sequences). A tissue-specific promoter may direct expression primarily in a desired tissue of interest, such as muscle, neuron, bone, skin, blood, specific organs (e.g. liver, pancreas), or particular cell types (e.g. lymphocytes). Regulatory elements may also direct expression in a temporal-dependent manner, such as in a cell-cycle dependent or developmental stage-dependent manner, which may or may not also be tissue or cell-type specific. In some embodiments, a vector comprises one or more pol III promoter (e.g. 1, 2, 3, 4, 5, or more pol III promoters), one or more pol II promoters (e.g. 1, 2, 3, 4, 5, or more pol II promoters), one or more pol I promoters (e.g. 1, 2, 3, 4, 5, or more pol I promoters), or combinations thereof Examples of pol III promoters include, but are not limited to, U6 and H1 promoters. Examples of pol II promoters include, but are not limited to, the retroviral Rous sarcoma virus (RSV) LTR promoter (optionally with the RSV enhancer), the cytomegalovirus (CMV) promoter (optionally with the CMV enhancer) [see, e.g., Boshart et al, Cell, 41:521-530 (1985)], the SV40 promoter, the dihydrofolate reductase promoter, the β-actin promoter, the phosphoglycerol kinase (PGK) promoter, and the EF1α promoter. Also encompassed by the term “regulatory element” are enhancer elements, such as WPRE; CMV enhancers; the R-U5′ segment in LTR of HTLV-I (Mol. Cell. Biol., Vol. 8(1), p. 466-472, 1988); SV40 enhancer; and the intron sequence between exons 2 and 3 of rabbit β-globin (Proc. Natl. Acad. Sci. USA., Vol. 78(3), p. 1527-31, 1981). It will be appreciated by those skilled in the art that the design of the expression vector can depend on such factors as the choice of the host cell to be transformed, the level of expression desired, etc. A vector can be introduced into host cells to thereby produce transcripts, proteins, or peptides, including fusion proteins or peptides, encoded by nucleic acids as described herein (e.g., clustered regularly interspersed short palindromic repeats (CRISPR) transcripts, proteins, enzymes, mutant forms thereof, fusion proteins thereof, etc.). With regards to regulatory sequences, mention is made of U.S. patent application Ser. No. 10/491,026, the contents of which are incorporated by reference herein in their entirety. With regards to promoters, mention is made of PCT publication WO 2011/028929 and U.S. application Ser. No. 12/511,940, the contents of which are incorporated by reference herein in their entirety.

Vectors can be designed for expression of CRISPR transcripts (e.g. nucleic acid transcripts, proteins, or enzymes) in prokaryotic or eukaryotic cells. For example, CRISPR transcripts can be expressed in bacterial cells such as Escherichia coli , insect cells (using baculovirus expression vectors), yeast cells, or mammalian cells. Suitable host cells are discussed further in Goeddel, GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990). Alternatively, the recombinant expression vector can be transcribed and translated in vitro, for example using T7 promoter regulatory sequences and T7 polymerase.

Vectors may be introduced and propagated in a prokaryote or prokaryotic cell. In some embodiments, a prokaryote is used to amplify copies of a vector to be introduced into a eukaryotic cell or as an intermediate vector in the production of a vector to be introduced into a eukaryotic cell (e.g. amplifying a plasmid as part of a viral vector packaging system). In some embodiments, a prokaryote is used to amplify copies of a vector and express one or more nucleic acids, such as to provide a source of one or more proteins for delivery to a host cell or host organism. Expression of proteins in prokaryotes is most often carried out in Escherichia coli with vectors containing constitutive or inducible promoters directing the expression of either fusion or non-fusion proteins. Fusion vectors add a number of amino acids to a protein encoded therein, such as to the amino terminus of the recombinant protein. Such fusion vectors may serve one or more purposes, such as: (i) to increase expression of recombinant protein; (ii) to increase the solubility of the recombinant protein; and (iii) to aid in the purification of the recombinant protein by acting as a ligand in affinity purification. Often, in fusion expression vectors, a proteolytic cleavage site is introduced at the junction of the fusion moiety and the recombinant protein to enable separation of the recombinant protein from the fusion moiety subsequent to purification of the fusion protein. Such enzymes, and their cognate recognition sequences, include Factor Xa, thrombin and enterokinase. Example fusion expression vectors include pGEX (Pharmacia Biotech Inc; Smith and Johnson, 1988. Gene 67: 31-40), pMAL (New England Biolabs, Beverly, Mass.) and pRIT5 (Pharmacia, Piscataway, N.J.) that fuse glutathione S-transferase (GST), maltose E binding protein, or protein A, respectively, to the target recombinant protein. Examples of suitable inducible non-fusion E. coli expression vectors include pTrc (Amrann et al., (1988) Gene 69:301-315) and pET 11d (Studier et al., GENE EXPRESSION TECHNOLOGY: METHODS IN ENZYMOLOGY 185, Academic Press, San Diego, Calif. (1990) 60-89). In some embodiments, a vector is a yeast expression vector. Examples of vectors for expression in yeast Saccharomyces cerivisae include pYepSec1 (Baldari, et al., 1987. EMBO J. 6: 229-234), pMFa (Kuijan and Herskowitz, 1982. Cell 30: 933-943), pJRY88 (Schultz et al., 1987. Gene 54: 113-123), pYES2 (Invitrogen Corporation, San Diego, Calif.), and picZ (InVitrogen Corp, San Diego, Calif.). In some embodiments, a vector drives protein expression in insect cells using baculovirus expression vectors. Baculovirus vectors available for expression of proteins in cultured insect cells (e.g., SF9 cells) include the pAc series (Smith, et al., 1983. Mol. Cell. Biol. 3: 2156-2165) and the pVL series (Lucklow and Summers, 1989. Virology 170: 31-39).

In some embodiments, a vector is capable of driving expression of one or more sequences in mammalian cells using a mammalian expression vector. Examples of mammalian expression vectors include pCDM8 (Seed, 1987. Nature 329: 840) and pMT2PC (Kaufman, et al., 1987. EMBO J. 6: 187-195). When used in mammalian cells, the expression vector's control functions are typically provided by one or more regulatory elements. For example, commonly used promoters are derived from polyoma, adenovirus 2, cytomegalovirus, simian virus 40, and others disclosed herein and known in the art. For other suitable expression systems for both prokaryotic and eukaryotic cells see, e.g., Chapters 16 and 17 of Sambrook, et al., MOLECULAR CLONING: A LABORATORY MANUAL. 2nd ed., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989.

In some embodiments, the recombinant mammalian expression vector is capable of directing expression of the nucleic acid preferentially in a particular cell type (e.g., tissue-specific regulatory elements are used to express the nucleic acid). Tissue-specific regulatory elements are known in the art. Non-limiting examples of suitable tissue-specific promoters include the albumin promoter (liver-specific; Pinkert, et al., 1987. Genes Dev. 1: 268-277), lymphoid-specific promoters (Calame and Eaton, 1988. Adv. Immunol. 43: 235-275), in particular promoters of T cell receptors (Winoto and Baltimore, 1989. EMBO J. 8: 729-733) and immunoglobulins (Baneiji, et al., 1983. Cell 33: 729-740; Queen and Baltimore, 1983. Cell 33: 741-748), neuron-specific promoters (e.g., the neurofilament promoter; Byrne and Ruddle, 1989. Proc. Natl. Acad. Sci. USA 86: 5473-5477), pancreas-specific promoters (Edlund, et al., 1985. Science 230: 912-916), and mammary gland-specific promoters (e.g., milk whey promoter; U.S. Pat. No. 4,873,316 and European Application Publication No. 264,166). Developmentally-regulated promoters are also encompassed, e.g., the murine hox promoters (Kessel and Gruss, 1990. Science 249: 374-379) and the a-fetoprotein promoter (Campes and Tilghman, 1989. Genes Dev. 3: 537-546). With regards to these prokaryotic and eukaryotic vectors, mention is made of U.S. Pat. No. 6,750,059, the contents of which are incorporated by reference herein in their entirety. Other embodiments of the invention may relate to the use of viral vectors, with regards to which mention is made of U.S. patent application Ser. No. 13/092,085, the contents of which are incorporated by reference herein in their entirety. Tissue-specific regulatory elements are known in the art and in this regard, mention is made of U.S. Pat. No. 7,776,321, the contents of which are incorporated by reference herein in their entirety. In some embodiments, a regulatory element is operably linked to one or more elements of a CRISPR system so as to drive expression of the one or more elements of the CRISPR system. In general, CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), also known as SPIDRs (SPacer Interspersed Direct Repeats), constitute a family of DNA loci that are usually specific to a particular bacterial species. The CRISPR locus comprises a distinct class of interspersed short sequence repeats (SSRs) that were recognized in E. coli (Ishino et al., J. Bacteriol., 169:5429-5433 [1987]; and Nakata et al., J. Bacteriol., 171:3553-3556 [1989]), and associated genes. Similar interspersed SSRs have been identified in Haloferax mediterranei, Streptococcus pyogenes, Anabaena , and Mycobacterium tuberculosis (See, Groenen et al., Mol. Microbiol., 10:1057-1065 [1993]; Hoe et al., Emerg. Infect. Dis., 5:254-263 [1999]; Masepohl et al., Biochim. Biophys. Acta 1307:26-30 [1996]; and Mojica et al., Mol. Microbiol., 17:85-93 [1995]). The CRISPR loci typically differ from other SSRs by the structure of the repeats, which have been termed short regularly spaced repeats (SRSRs) (Janssen et al., OMICS J. Integ. Biol., 6:23-33 [2002]; and Mojica et al., Mol. Microbiol., 36:244-246 [2000]). In general, the repeats are short elements that occur in clusters that are regularly spaced by unique intervening sequences with a substantially constant length (Mojica et al., [2000], supra). Although the repeat sequences are highly conserved between strains, the number of interspersed repeats and the sequences of the spacer regions typically differ from strain to strain (van Embden et al., J. Bacteriol., 182:2393-2401 [2000]). CRISPR loci have been identified in more than 40 prokaryotes (See e.g., Jansen et al., Mol. Microbiol., 43:1565-1575 [2002]; and Mojica et al., [2005]) including, but not limited to Aeropyrum, Pyrobaculum, Sulfolobus, Archaeoglobus, Haloarcula, Methanobacterium, Methanococcus, Methanosarcina, Methanopyrus, Pyrococcus, Picrophilus, Thermoplasma, Corynebacterium, Mycobacterium, Streptomyces, Aquifex, Porphyromonas, Chlorobium, Thermus, Bacillus, Listeria, Staphylococcus, Clostridium, Thermoanaerobacter, Mycoplasma, Fusobacterium, Azoarcus, Chromobacterium, Neisseria, Nitrosomonas, Desulfovibrio, Geobacter, Myxococcus, Campylobacter, Wolinella, Acinetobacter, Erwinia, Escherichia, Legionella, Methylococcus, Pasteurella, Photobacterium, Salmonella, Xanthomonas, Yersinia, Treponema , and Thermotoga.

Typically, in the context of an endogenous nucleic acid-targeting system, formation of a nucleic acid-targeting complex (comprising a guide RNA hybridized to a target sequence and complexed with one or more nucleic acid-targeting effector modules) results in cleavage of one or both RNA strands in or near (e.g. within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from) the target sequence. In some embodiments, one or more vectors driving expression of one or more elements of a nucleic acid-targeting system are introduced into a host cell such that expression of the elements of the nucleic acid-targeting system direct formation of a nucleic acid-targeting complex at one or more target sites. For example, a nucleic acid-targeting effector module and a guide RNA could each be operably linked to separate regulatory elements on separate vectors. Alternatively, two or more of the elements expressed from the same or different regulatory elements, may be combined in a single vector, with one or more additional vectors providing any components of the nucleic acid-targeting system not included in the first vector. Nucleic acid-targeting system elements that are combined in a single vector may be arranged in any suitable orientation, such as one element located 5′ with respect to (“upstream” of) or 3′ with respect to (“downstream” of) a second element. The coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and oriented in the same or opposite direction. In some embodiments, a single promoter drives expression of a transcript encoding a nucleic acid-targeting effector module and a guide RNA embedded within one or more intron sequences (e.g. each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the nucleic acid-targeting effector module and guide RNA are operably linked to and expressed from the same promoter.

Ways to package inventive Cpf1 coding nucleic acid molecules, e.g., DNA, into vectors, e.g., viral vectors, to mediate genome modification in vivo may include:

To achieve NHEJ-mediated gene knockout: Single virus vector: Vector containing two or more expression cassettes: Promoter-Cpf1 coding nucleic acid molecule-terminator Promoter-gRNA 1-terminator Promoter-gRNA2-terminator Promoter-gRNA(N)-terminator (up to size limit of vector) Double virus vector: Vector 1 containing one expression cassette for driving the expression of Cpf1 Promoter-Cpf1 coding nucleic acid molecule-terminator Vector 2 containing one more expression cassettes for driving the expression of one or more guideRNAs Promoter-gRNA 1-terminator Promoter-gRNA(N)-terminator (up to size limit of vector) To mediate homology-directed repair. In addition to the single and double virus vector approaches described above, an additional vector can be used to deliver a homology-direct repair template.

The promoter used to drive Cpf1 coding nucleic acid molecule expression can include:

AAV ITR can serve as a promoter: this is advantageous for eliminating the need for an additional promoter element (which can take up space in the vector). The additional space freed up can be used to drive the expression of additional elements (gRNA, etc.). Also, ITR activity is relatively weaker, so can be used to reduce potential toxicity due to over expression of Cpf1. For ubiquitous expression, promoters that can be used include: CMV, CAG, CBh, PGK, SV40, Ferritin heavy or light chains, etc.

For brain or other CNS expression, can use promoters: Synapsin I for all neurons, CaMKIIalpha for excitatory neurons, GAD67 or GAD65 or VGAT for GABAergic neurons, etc.

For liver expression, can use Albumin promoter.

For lung expression, can use SP-B.

For endothelial cells, can use ICAM.

For hematopoietic cells can use IFNbeta or CD45.

For Osteoblasts can one can use the OG-2.

The promoter used to drive guide RNA can include:

Pol III promoters such as U6 or Use of Pol II promoter and intronic cassettes to express gRNA

Adeno Associated Virus (AAV)

Cpf1 and one or more guide RNA can be delivered using adeno associated virus (AAV), lentivirus, adenovirus or other plasmid or viral vector types, in particular, using formulations and doses from, for example, U.S. Pat. No. 8,454,972 (formulations, doses for adenovirus), U.S. Pat. No. 8,404,658 (formulations, doses for AAV) and U.S. Pat. No. 5,846,946 (formulations, doses for DNA plasmids) and from clinical trials and publications regarding the clinical trials involving lentivirus, AAV and adenovirus. For examples, for AAV, the route of administration, formulation and dose can be as in U.S. Pat. No. 8,454,972 and as in clinical trials involving AAV. For Adenovirus, the route of administration, formulation and dose can be as in U.S. Pat. No. 8,404,658 and as in clinical trials involving adenovirus. For plasmid delivery, the route of administration, formulation and dose can be as in U.S. Pat. No. 5,846,946 and as in clinical studies involving plasmids. Doses may be based on or extrapolated to an average 70 kg individual (e.g. a male adult human), and can be adjusted for patients, subjects, mammals of different weight and species. Frequency of administration is within the ambit of the medical or veterinary practitioner (e.g., physician, veterinarian), depending on usual factors including the age, sex, general health, other conditions of the patient or subject and the particular condition or symptoms being addressed. The viral vectors can be injected into the tissue of interest. For cell-type specific genome modification, the expression of Cpf1 can be driven by a cell-type specific promoter. For example, liver-specific expression might use the Albumin promoter and neuron-specific expression (e.g. for targeting CNS disorders) might use the Synapsin I promoter.

In terms of in vivo delivery, AAV is advantageous over other viral vectors for a couple of reasons:

Low toxicity (this may be due to the purification method not requiring ultra centrifugation of cell particles that can activate the immune response) and Low probability of causing insertional mutagenesis because it doesn't integrate into the host genome.

AAV has a packaging limit of 4.5 or 4.75 Kb. This means that Cpf1 as well as a promoter and transcription terminator have to be all fit into the same viral vector. Constructs larger than 4.5 or 4.75 Kb will lead to significantly reduced virus production. SpCas9 is quite large, the gene itself is over 4.1 Kb, which makes it difficult for packing into AAV. Therefore embodiments of the invention include utilizing homologs of Cpf1 that are shorter. For example:

rAAV vectors are preferably produced in insect cells, e.g., Spodoptera frugiperda Sf9 insect cells, grown in serum-free suspension culture. Serum-free insect cells can be purchased from commercial vendors, e.g., Sigma Aldrich (EX-CELL 405).

These species are therefore, in general, preferred Cpf1 species.

As to AAV, the AAV can be AAV1, AAV2, AAV5 or any combination thereof. One can select the AAV of the AAV with regard to the cells to be targeted; e.g., one can select AAV serotypes 1, 2, 5 or a hybrid capsid AAV1, AAV2, AAV5 or any combination thereof for targeting brain or neuronal cells; and one can select AAV4 for targeting cardiac tissue. AAV8 is useful for delivery to the liver. The herein promoters and vectors are preferred individually. A tabulation of certain AAV serotypes as to these cells (see Grimm, D. et al, J. Virol. 82: 5887-5911 (2008)) is as follows:

Lentivirus

Lentiviruses are complex retroviruses that have the ability to infect and express their genes in both mitotic and post-mitotic cells. The most commonly known lentivirus is the human immunodeficiency virus (HIV), which uses the envelope glycoproteins of other viruses to target a broad range of cell types.

Lentiviruses may be prepared as follows. After cloning pCasES10 (which contains a lentiviral transfer plasmid backbone), HEK293FT at low passage (p=5) were seeded in a T-75 flask to 50% confluence the day before transfection in DMEM with 10% fetal bovine serum and without antibiotics. After 20 hours, media was changed to OptiMEM (serum-free) media and transfection was done 4 hours later. Cells were transfected with 10 μg of lentiviral transfer plasmid (pCasES10) and the following packaging plasmids: 5 μg of pMD2.G (VSV-g pseudotype), and 7.5 μg of psPAX2 (gag/poi/rev/tat). Transfection was done in 4 mL OptiMEM with a cationic lipid delivery agent (50 μL Lipofectamine 2000 and 100 μl Plus reagent). After 6 hours, the media was changed to antibiotic-free DMEM with 10% fetal bovine serum. These methods use serum during cell culture, but serum-free methods are preferred.

Lentivirus may be purified as follows. Viral supernatants were harvested after 48 hours. Supernatants were first cleared of debris and filtered through a 0.45 μm low protein binding (PVDF) filter. They were then spun in a ultracentrifuge for 2 hours at 24,000 rpm. Viral pellets were resuspended in 50 μl of DMEM overnight at 4 C. They were then aliquoted and immediately frozen at −80° C.

In another embodiment, minimal non-primate lentiviral vectors based on the equine infectious anemia virus (EIAV) are also contemplated, especially for ocular gene therapy (see, e.g., Balagaan, J Gene Med 2006; 8: 275-285). In another embodiment, RetinoStat®, an equine infectious anemia virus-based lentiviral gene therapy vector that expresses angiostatic proteins endostatin and angiostatin that is delivered via a subretinal injection for the treatment of the web form of age-related macular degeneration is also contemplated (see, e.g., Binley et al., HUMAN GENE THERAPY 23:980-991 (September 2012)) and this vector may be modified for the CRISPR-Cas system of the present invention.

In another embodiment, self-inactivating lentiviral vectors with an siRNA targeting a common exon shared by HIV tat/rev, a nucleolar-localizing TAR decoy, and an anti-CCR5-specific hammerhead ribozyme (see, e.g., DiGiusto et al. (2010) Sci Transl Med 2:36ra43) may be used/and or adapted to the CRISPR-Cas system of the present invention. A minimum of 2.5×106 CD34+ cells per kilogram patient weight may be collected and prestimulated for 16 to 20 hours in X-VIVO 15 medium (Lonza) containing 2 μmol/L-glutamine, stem cell factor (100 ng/ml), Flt-3 ligand (Flt-3L) (100 ng/ml), and thrombopoietin (10 ng/ml) (CellGenix) at a density of 2×106 cells/ml. Prestimulated cells may be transduced with lentiviral at a multiplicity of infection of 5 for 16 to 24 hours in 75-cm2 tissue culture flasks coated with fibronectin (25 mg/cm2) (RetroNectin, Takara Bio Inc.).

Lentiviral vectors have been disclosed as in the treatment for Parkinson's Disease, see, e.g., US Patent Publication No. 20120295960 and U.S. Pat. Nos. 7,303,910 and 7,351,585. Lentiviral vectors have also been disclosed for the treatment of ocular diseases, see e.g., US Patent Publication Nos. 20060281180, 20090007284, US20110117189; US20090017543; US20070054961, US20100317109. Lentiviral vectors have also been disclosed for delivery to the brain, see, e.g., US Patent Publication Nos. US20110293571; US20110293571, US20040013648, US20070025970, US20090111106 and U.S. Pat. No. 7,259,015.

Use of Minimal Promoters

The present application provides a vector for delivering an effector protein and at least one CRISPR guide RNA to a cell comprising a minimal promoter operably linked to a polynucleotide sequence encoding the effector protein and a second minimal promoter operably linked to a polynucleotide sequence encoding at least one guide RNA, wherein the length of the vector sequence comprising the minimal promoters and polynucleotide sequences is less than 4.4Kb. In an embodiment, the vector is an AAV vector. In another embodiment, the effector protein is a CRISPR enzyme. In a further embodiment, the CRISPR enzyme is SaCas9, Cpf1, Cas13b or C2c2.

In a related aspect, the invention provides a lentiviral vector for delivering an effector protein and at least one CRISPR guide RNA to a cell comprising a promoter operably linked to a polynucleotide sequence encoding Cpf1 and a second promoter operably linked to a polynucleotide sequence encoding at least one guide RNA, wherein the polynucleotide sequences are in reverse orientation.

In another aspect, the invention provides a method of expressing an effector protein and guide RNA in a cell comprising introducing the vector according any of the vector delivery systems disclosed herein. In an embodiment of the vector for delivering an effector protein, the minimal promoter is the Mecp2 promoter, tRNA promoter, or U6. In a further embodiment, the minimal promoter is tissue specific.

Optimization of CRISPR-Cas Systems

In another aspect, the present invention relates to methods for developing or designing CRISPR-Cas systems. In an aspect, the present invention relates to methods for developing or designing CRISPR-Cas system based therapy or therapeutics. The present invention in particular relates to methods for improving CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics. Key characteristics of successful CRISPR-Cas systems, such as CRISPR-Cas system based therapy or therapeutics involve high specificity, high efficacy, and high safety. High specificity and high safety can be achieved among others by reduction of off-target effects.

Accordingly, in another aspect, the invention relates to a method as described herein, comprising selection of one or more (therapeutic) target, selecting one or more CRISPR-Cas system functionality, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality. In a related aspect, the invention relates to a method as described herein, comprising (a) selecting one or more (therapeutic) target loci, (b) selecting one or more CRISPR-Cas system functionalities, (c) optionally selecting one or more modes of delivery, and preparing, developing, or designing a CRISPR-Cas system selected based on steps (a)-(c).

In certain embodiments, CRISPR-Cas system functionality comprises genomic mutation. In certain embodiments, CRISPR-Cas system functionality comprises single genomic mutation. In certain embodiments, CRISPR-Cas system functionality comprises multiple genomic mutation. In certain embodiments, CRISPR-Cas system functionality comprises gene knockout. In certain embodiments, CRISPR-Cas system functionality comprises single gene knockout. In certain embodiments, CRISPR-Cas system functionality comprises multiple gene knockout. In certain embodiments, CRISPR-Cas system functionality comprises gene correction. In certain embodiments, CRISPR-Cas system functionality comprises single gene correction. In certain embodiments, CRISPR-Cas system functionality comprises multiple gene correction. In certain embodiments, CRISPR-Cas system functionality comprises genomic region correction. In certain embodiments, CRISPR-Cas system functionality comprises single genomic region correction. In certain embodiments, CRISPR-Cas system functionality comprises multiple genomic region correction. In certain embodiments, CRISPR-Cas system functionality comprises gene deletion. In certain embodiments, CRISPR-Cas system functionality comprises single gene deletion. In certain embodiments, CRISPR-Cas system functionality comprises multiple gene deletion. In certain embodiments, CRISPR-Cas system functionality comprises genomic region deletion. In certain embodiments, CRISPR-Cas system functionality comprises single genomic region deletion. In certain embodiments, CRISPR-Cas system functionality comprises multiple genomic region deletion. In certain embodiments, CRISPR-Cas system functionality comprises modulation of gene or genomic region functionality. In certain embodiments, CRISPR-Cas system functionality comprises modulation of single gene or genomic region functionality. In certain embodiments, CRISPR-Cas system functionality comprises modulation of multiple gene or genomic region functionality. In certain embodiments, CRISPR-Cas system functionality comprises gene or genomic region functionality, such as gene or genomic region activity. In certain embodiments, CRISPR-Cas system functionality comprises single gene or genomic region functionality, such as gene or genomic region activity. In certain embodiments, CRISPR-Cas system functionality comprises multiple gene or genomic region functionality, such as gene or genomic region activity. In certain embodiments, CRISPR-Cas system functionality comprises modulation gene activity or accessibility optionally leading to transcriptional and/or epigenetic gene or genomic region activation or gene or genomic region silencing. In certain embodiments, CRISPR-Cas system functionality comprises modulation single gene activity or accessibility optionally leading to transcriptional and/or epigenetic gene or genomic region activation or gene or genomic region silencing. In certain embodiments, CRISPR-Cas system functionality comprises modulation multiple gene activity or accessibility optionally leading to transcriptional and/or epigenetic gene or genomic region activation or gene or genomic region silencing.

The methods as described herein may further involve selection of the CRISPR-Cas system mode of delivery. In certain embodiments, gRNA (and tracr, if and where needed, optionally provided as a sgRNA) and/or CRISPR effector protein are or are to be delivered. In certain embodiments, gRNA (and tracr, if and where needed, optionally provided as a sgRNA) and/or CRISPR effector mRNA are or are to be delivered. In certain embodiments, gRNA (and tracr, if and where needed, optionally provided as a sgRNA) and/or CRISPR effector provided in a DNA-based expression system are or are to be delivered. In certain embodiments, delivery of the individual CRISPR-Cas system components comprises a combination of the above modes of delivery. In certain embodiments, delivery comprises delivering gRNA and/or CRISPR effector protein, delivering gRNA and/or CRISPR effector mRNA, or delivering gRNA and/or CRISPR effector as a DNA based expression system.

Accordingly, in an aspect, the invention relates to a method as described herein, comprising selection of one or more (therapeutic) target, selecting CRISPR-Cas system functionality, selecting CRISPR-Cas system mode of delivery, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality.

The methods as described herein may further involve selection of the CRISPR-Cas system delivery vehicle and/or expression system. Delivery vehicles and expression systems are described herein elsewhere. By means of example, delivery vehicles of nucleic acids and/or proteins include nanoparticles, liposomes, etc. Delivery vehicles for DNA, such as DNA-based expression systems include for instance biolistics, viral based vector systems (e.g. adenoviral, AAV, lentiviral), etc. the skilled person will understand that selection of the mode of delivery, as well as delivery vehicle or expression system may depend on for instance the cell or tissues to be targeted. In certain embodiments, a delivery vehicle and/or expression system for delivering the CRISPR-Cas systems or components thereof comprises liposomes, lipid particles, nanoparticles, biolistics, or viral-based expression/delivery systems.

Accordingly, in an aspect, the invention relates to a method as described herein, comprising selection of one or more (therapeutic) target, selecting CRISPR-Cas system functionality, selecting CRISPR-Cas system mode of delivery, selecting CRISPR-Cas system delivery vehicle or expression system, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality.

Optimization of selected parameters or variables in the methods as described herein may result in optimized or improved CRISPR-Cas system, such as CRISPR-Cas system based therapy or therapeutic, specificity, efficacy, and/or safety. In certain embodiments, one or more of the following parameters or variables are taken into account, are selected, or are optimized in the methods of the invention as described herein: CRISPR effector specificity, gRNA specificity, CRISPR-Cas complex specificity, PAM restrictiveness, PAM type (natural or modified), PAM nucleotide content, PAM length, CRISPR effector activity, gRNA activity, CRISPR-Cas complex activity, target cleavage efficiency, target site selection, target sequence length, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, CRISPR effector stability, CRISPR effector mRNA stability, gRNA stability, CRISPR-Cas complex stability, CRISPR effector protein or mRNA immunogenicity or toxicity, gRNA immunogenicity or toxicity, CRISPR-Cas complex immunogenicity or toxicity, CRISPR effector protein or mRNA dose or titer, gRNA dose or titer, CRISPR-Cas complex dose or titer, CRISPR effector protein size, CRISPR effector expression level, gRNA expression level, CRISPR-Cas complex expression level, CRISPR effector spatiotemporal expression, gRNA spatiotemporal expression, CRISPR-Cas complex spatiotemporal expression.

In certain embodiments, selecting one or more CRISP-Cas system functionalities comprises selecting one or more of an optimal effector protein, an optimal guide RNA, or both.

In certain embodiments, selecting an optimal effector protein comprises optimizing one or more of effector protein type, size, PAM specificity, effector protein stability, immunogenicity or toxicity, functional specificity, and efficacy, or other CRISPR effector associated parameters or variables as described herein elsewhere.

In certain embodiments, the effector protein is a naturally occurring or modified effector protein.

In certain embodiments, the modified effector protein is a nickase, a deaminase, or a deactivated effector protein.

In certain embodiments, optimizing size comprises selecting a protein effector having a minimal size.

In certain embodiments, optimizing a PAM specificity comprises selecting an effector protein having a modified PAM specificity.

In certain embodiments, optimizing effector protein stability comprises selecting an effector protein having a short half-life while maintaining sufficient activity, such as by selecting an appropriate CRISPR effector orthologue having a specific half-life or stability.

In certain embodiments, optimizing immunogenicity or toxicity comprises minimizing effector protein immunogenicity or toxicity by protein modifications.

In certain embodiments, optimizing functional specific comprises selecting a protein effector with reduced tolerance of mismatches and/or bulges between the guide RNA and one or more target loci.

In certain embodiments, optimizing efficacy comprises optimizing overall efficiency, epigenetic tolerance, or both.

In certain embodiments, maximizing overall efficiency comprises selecting an effector protein with uniform enzyme activity across target loci with varying chromatin complexity, selecting an effector protein with enzyme activity limited to areas of open chromatin accessibility.

In certain embodiments, chromatin accessibility is measured using one or more of ATAC-seq, or a DNA-proximity ligation assay.

In certain embodiments, optimizing epigenetic tolerance comprises optimizing methylation tolerance, epigenetic mark competition, or both.

In certain embodiments, optimizing methylation tolerance comprises selecting an effector protein that modify methylated DNA.

In certain embodiments, optimizing epigenetic tolerance comprises selecting an effector protein unable to modify silenced regions of a chromosome, selecting an effector protein able to modify silenced regions of a chromosome, or selecting target loci not enriched for epigenetic markers.

In certain embodiments, selecting an optimized guide RNA comprises optimizing gRNA stability, gRNA immunogenicity, or both, or other gRNA associated parameters or variables as described herein elsewhere.

In certain embodiments, optimizing gRNA stability and/or gRNA immunogenicity comprises RNA modification, or other gRNA associated parameters or variables as described herein elsewhere. In certain embodiments, the modification comprises removing 1-3 nucleotides form the 3′ end of a target complementarity region of the gRNA. In certain embodiments, modification comprises an extended gRNA and/or trans RNA/DNA element that create stable structures in the gRNA that compete with gRNA base pairing at a target of off-target loci, or extended complimentary nucleotides between the gRNA and target sequence, or both.

In certain embodiments, the mode of delivery comprises delivering gRNA and/or CRISPR effector protein, delivering gRNA and/or CRISPR effector mRNA, or delivery gRNA and/or CRISPR effector as a DNA based expression system. In certain embodiments, the mode of delivery further comprises selecting a delivery vehicle and/or expression systems from the group consisting of liposomes, lipid particles, nanoparticles, biolistics, or viral-based expression/delivery systems. In certain embodiments, expression is spatiotemporal expression is optimized by choice of conditional and/or inducible expression systems, including controllable CRISPR effector activity optionally a destabilized CRISPR effector and/or a split CRISPR effector, and/or cell- or tissue-specific expression system.

The above described parameters or variables, as well as means for optimization are described herein elsewhere. By means of example, and without limitation, parameter or variable optimization may be achieved as follows. CRISPR effector specificity may be optimized by selecting the most specific CRISPR effector. This may be achieved for instance by selecting the most specific CRISPR effector orthologue or by specific CRISPR effector mutations which increase specificity. gRNA specificity may be optimized by selecting the most specific gRNA. This may be achieved for instance by selecting gRNA having low homology, i.e. at least one or preferably more, such as at least 2, or preferably at least 3, mismatches to off-target sites. CRISPR-Cas complex specificity may be optimized by increasing CRISPR effector specificity and/or gRNA specificity as above. PAM restrictiveness may be optimized by selecting a CRISPR effector having to most restrictive PAM recognition. This may be achieved for instance by selecting a CRISPR effector orthologue having more restrictive PAM recognition or by specific CRISPR effector mutations which increase or alter PAM restrictiveness. PAM type may be optimized for instance by selecting the appropriate CRISPR effector, such as the appropriate CRISPR effector recognizing a desired PAM type. The CRISPR effector or PAM type may be naturally occurring or may for instance be optimized based on CRISPR effector mutants having an altered PAM recognition, or PAM recognition repertoire. PAM nucleotide content may for instance be optimized by selecting the appropriate CRISPR effector, such as the appropriate CRISPR effector recognizing a desired PAM nucleotide content. The CRISPR effector or PAM type may be naturally occurring or may for instance be optimized based on CRISPR effector mutants having an altered PAM recognition, or PAM recognition repertoire. PAM length may for instance be optimized by selecting the appropriate CRISPR effector, such as the appropriate CRISPR effector recognizing a desired PAM nucleotide length. The CRISPR effector or PAM type may be naturally occurring or may for instance be optimized based on CRISPR effector mutants having an altered PAM recognition, or PAM recognition repertoire. Target length or target sequence length may for instance be optimized by selecting the appropriate CRISPR effector, such as the appropriate CRISPR effector recognizing a desired target or target sequence nucleotide length. Alternatively, or in addition, the target (sequence) length may be optimized by providing a target having a length deviating from the target (sequence) length typically associated with the CRISPR effector, such as the naturally occurring CRISPR effector. The CRISPR effector or target (sequence) length may be naturally occurring or may for instance be optimized based on CRISPR effector mutants having an altered target (sequence) length recognition, or target (sequence) length recognition repertoire. For instance, increasing or decreasing target (sequence) length may influence target recognition and/or off-target recognition. CRISPR effector activity may be optimized by selecting the most active CRISPR effector. This may be achieved for instance by selecting the most active CRISPR effector orthologue or by specific CRISPR effector mutations which increase activity. The ability of the CRISPR effector protein to access regions of high chromatin accessibility, may be optimized by selecting the appropriate CRISPR effector or mutant thereof, and may take into account the size of the CRISPR effector, charge, or other dimensional variables etc. The degree of uniform CRISPR effector activity may be optimized by selecting the appropriate CRISPR effector or mutant thereof, and may take into account CRISPR effector specificity and/or activity, PAM specificity, target length, mismatch tolerance, epigenetic tolerance, CRISPR effector and/or gRNA stability and/or half-life, CRISPR effector and/or gRNA immunogenicity and/or toxicity, etc. gRNA activity may be optimized by selecting the most active gRNA. This may be achieved for instance by increasing gRNA stability through RNA modification. CRISPR-Cas complex activity may be optimized by increasing CRISPR effector activity and/or gRNA activity as above. The target site selection may be optimized by selecting the optimal position of the target site within a gene, locus or other genomic region. The target site selection may be optimized by optimizing target location comprises selecting a target sequence with a gene, locus, or other genomic region having low variability. This may be achieved for instance by selecting a target site in an early and/or conserved exon or domain (i.e. having low variability, such as polymorphisms, within a population). Alternatively, the target site may be selected by minimization of off-target effects (e.g. off-targets qualified as having 1-5, 1-4, or preferably 1-3 mismatches compared to target and/or having one or more PAM mismatches, such as distal PAM mismatches), preferably also taking into account variability within a population. CRISPR effector stability may be optimized by selecting CRISPR effector having appropriate half-life, such as preferably a short half-life while still capable of maintaining sufficient activity. This may be achieved for instance by selecting an appropriate CRISPR effector orthologue having a specific half-life or by specific CRISPR effector mutations or modifications which affect half-life or stability, such as inclusion (e.g. fusion) of stabilizing or destabilizing domains or sequences. CRISPR effector mRNA stability may be optimized by increasing or decreasing CRISPR effector mRNA stability. This may be achieved for instance by increasing or decreasing CRISPR effector mRNA stability through mRNA modification. gRNA stability may be optimized by increasing or decreasing gRNA stability. This may be achieved for instance by increasing or decreasing gRNA stability through RNA modification. CRISPR-Cas complex stability may be optimized by increasing or decreasing CRISPR effector stability and/or gRNA stability as above. CRISPR effector protein or mRNA immunogenicity or toxicity may be optimized by decreasing CRISPR effector protein or mRNA immunogenicity or toxicity. This may be achieved for instance by mRNA or protein modifications. Similarly, in case of DNA based expression systems, DNA immunogenicity or toxicity may be decreased. gRNA immunogenicity or toxicity may be optimized by decreasing gRNA immunogenicity or toxicity. This may be achieved for instance by gRNA modifications. Similarly, in case of DNA based expression systems, DNA immunogenicity or toxicity may be decreased. CRISPR-Cas complex immunogenicity or toxicity may be optimized by decreasing CRISPR effector immunogenicity or toxicity and/or gRNA immunogenicity or toxicity as above, or by selecting the least immunogenic or toxic CRISPR effector/gRNA combination. Similarly, in case of DNA based expression systems, DNA immunogenicity or toxicity may be decreased. CRISPR effector protein or mRNA dose or titer may be optimized by selecting dosage or titer to minimize toxicity and/or maximize specificity and/or efficacy. gRNA dose or titer may be optimized by selecting dosage or titer to minimize toxicity and/or maximize specificity and/or efficacy. CRISPR-Cas complex dose or titer may be optimized by selecting dosage or titer to minimize toxicity and/or maximize specificity and/or efficacy. CRISPR effector protein size may be optimized by selecting minimal protein size to increase efficiency of delivery, in particular for virus mediated delivery. CRISPR effector, gRNA, or CRISPR-Cas complex expression level may be optimized by limiting (or extending) the duration of expression and/or limiting (or increasing) expression level. This may be achieved for instance by using self-inactivating CRISPR-Cas systems, such as including a self-targeting (e.g. CRISPR effector targeting) gRNA, by using viral vectors having limited expression duration, by using appropriate promoters for low (or high) expression levels, by combining different delivery methods for individual CRISP-Cas system components, such as virus mediated delivery of CRISPR-effector encoding nucleic acid combined with non-virus mediated delivery of gRNA, or virus mediated delivery of gRNA combined with non-virus mediated delivery of CRISPR effector protein or mRNA. CRISPR effector, gRNA, or CRISPR-Cas complex spatiotemporal expression may be optimized by appropriate choice of conditional and/or inducible expression systems, including controllable CRISPR effector activity optionally a destabilized CRISPR effector and/or a split CRISPR effector, and/or cell- or tissue-specific expression systems.

In an aspect, the invention relates to a method as described herein, comprising selection of one or more (therapeutic) target, selecting CRISPR-Cas system functionality, selecting CRISPR-Cas system mode of delivery, selecting CRISPR-Cas system delivery vehicle or expression system, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, optionally wherein the parameters or variables are one or more selected from CRISPR effector specificity, gRNA specificity, CRISPR-Cas complex specificity, PAM restrictiveness, PAM type (natural or modified), PAM nucleotide content, PAM length, CRISPR effector activity, gRNA activity, CRISPR-Cas complex activity, target cleavage efficiency, target site selection, target sequence length, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, CRISPR effector stability, CRISPR effector mRNA stability, gRNA stability, CRISPR-Cas complex stability, CRISPR effector protein or mRNA immunogenicity or toxicity, gRNA immunogenicity or toxicity, CRISPR-Cas complex immunogenicity or toxicity, CRISPR effector protein or mRNA dose or titer, gRNA dose or titer, CRISPR-Cas complex dose or titer, CRISPR effector protein size, CRISPR effector expression level, gRNA expression level, CRISPR-Cas complex expression level, CRISPR effector spatiotemporal expression, gRNA spatiotemporal expression, CRISPR-Cas complex spatiotemporal expression.

In an aspect, the invention relates to a method as described herein, comprising optionally selecting one or more (therapeutic) target, optionally selecting one or more CRISPR-Cas system functionality, optionally selecting one or more CRISPR-Cas system mode of delivery, optionally selecting one or more CRISPR-Cas system delivery vehicle or expression system, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, wherein specificity, efficacy, and/or safety are optimized, and optionally wherein optimization of specificity comprises optimizing one or more parameters or variables selected from CRISPR effector specificity, gRNA specificity, CRISPR-Cas complex specificity, PAM restrictiveness, PAM type (natural or modified), PAM nucleotide content, PAM length, wherein optimization of efficacy comprises optimizing one or more parameters or variables selected from CRISPR effector activity, gRNA activity, CRISPR-Cas complex activity, target cleavage efficiency, target site selection, target sequence length, CRISPR effector protein size, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, and wherein optimization of safety comprises optimizing one or more parameters or variables selected from CRISPR effector stability, CRISPR effector mRNA stability, gRNA stability, CRISPR-Cas complex stability, CRISPR effector protein or mRNA immunogenicity or toxicity, gRNA immunogenicity or toxicity, CRISPR-Cas complex immunogenicity or toxicity, CRISPR effector protein or mRNA dose or titer, gRNA dose or titer, CRISPR-Cas complex dose or titer, CRISPR effector expression level, gRNA expression level, CRISPR-Cas complex expression level, CRISPR effector spatiotemporal expression, gRNA spatiotemporal expression, CRISPR-Cas complex spatiotemporal expression.

In an aspect, the invention relates to a method as described herein, comprising selecting one or more (therapeutic) target, selecting one or more CRISPR-Cas system functionality, selecting one or more CRISPR-Cas system mode of delivery, selecting one or more CRISPR-Cas system delivery vehicle or expression system, and optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, wherein specificity, efficacy, and/or safety are optimized, and optionally wherein optimization of specificity comprises optimizing one or more parameters or variables selected from CRISPR effector specificity, gRNA specificity, CRISPR-Cas complex specificity, PAM restrictiveness, PAM type (natural or modified), PAM nucleotide content, PAM length, wherein optimization of efficacy comprises optimizing one or more parameters or variables selected from CRISPR effector activity, gRNA activity, CRISPR-Cas complex activity, target cleavage efficiency, target site selection, target sequence length, CRISPR effector protein size, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, and wherein optimization of safety comprises optimizing one or more parameters or variables selected from CRISPR effector stability, CRISPR effector mRNA stability, gRNA stability, CRISPR-Cas complex stability, CRISPR effector protein or mRNA immunogenicity or toxicity, gRNA immunogenicity or toxicity, CRISPR-Cas complex immunogenicity or toxicity, CRISPR effector protein or mRNA dose or titer, gRNA dose or titer, CRISPR-Cas complex dose or titer, CRISPR effector expression level, gRNA expression level, CRISPR-Cas complex expression level, CRISPR effector spatiotemporal expression, gRNA spatiotemporal expression, CRISPR-Cas complex spatiotemporal expression.

In an aspect, the invention relates to a method as described herein, comprising optimization of selected parameters or variables associated with the CRISPR-Cas system and/or its functionality, wherein specificity, efficacy, and/or safety are optimized, and optionally wherein optimization of specificity comprises optimizing one or more parameters or variables selected from CRISPR effector specificity, gRNA specificity, CRISPR-Cas complex specificity, PAM restrictiveness, PAM type (natural or modified), PAM nucleotide content, PAM length, wherein optimization of efficacy comprises optimizing one or more parameters or variables selected from CRISPR effector activity, gRNA activity, CRISPR-Cas complex activity, target cleavage efficiency, target site selection, target sequence length, CRISPR effector protein size, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, and wherein optimization of safety comprises optimizing one or more parameters or variables selected from CRISPR effector stability, CRISPR effector mRNA stability, gRNA stability, CRISPR-Cas complex stability, CRISPR effector protein or mRNA immunogenicity or toxicity, gRNA immunogenicity or toxicity, CRISPR-Cas complex immunogenicity or toxicity, CRISPR effector protein or mRNA dose or titer, gRNA dose or titer, CRISPR-Cas complex dose or titer, CRISPR effector expression level, gRNA expression level, CRISPR-Cas complex expression level, CRISPR effector spatiotemporal expression, gRNA spatiotemporal expression, CRISPR-Cas complex spatiotemporal expression.

It will be understood that the parameters or variables to be optimized as well as the nature of optimization may depend on the (therapeutic) target, the CRISPR-Cas system functionality, the CRISPR-Cas system mode of delivery, and/or the CRISPR-Cas system delivery vehicle or expression system.

In an aspect, the invention relates to a method as described herein, comprising optimization of gRNA specificity at the population level. Preferably, said optimization of gRNA specificity comprises minimizing gRNA target site sequence variation across a population and/or minimizing gRNA off-target incidence across a population.

In an aspect, the invention relates to a method for developing or designing a CRISPR-Cas system, optionally a CRISPR-Cas system based therapy or therapeutic, comprising (a) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, and from said selected target sites subselecting target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, or (b) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, or selecting for a (therapeutic) locus of interest gRNA target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, and optionally estimating the number of (sub)selected target sites needed to treat or otherwise modulate or manipulate a population, optionally validating one or more of the (sub)selected target sites for an individual subject, optionally designing one or more gRNA recognizing one or more of said (sub)selected target sites.

In an aspect, the invention relates to a method for developing or designing a gRNA for use in a CRISPR-Cas system, optionally a CRISPR-Cas system based therapy or therapeutic, comprising (a)

selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, and from said selected target sites subselecting target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, or (b) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, or selecting for a (therapeutic) locus of interest gRNA target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, and optionally estimating the number of (sub)selected target sites needed to treat or otherwise modulate or manipulate a population, optionally validating one or more of the (sub)selected target sites for an individual subject, optionally designing one or more gRNA recognizing one or more of said (sub)selected target sites.

In an aspect, the invention relates to a method for developing or designing a CRISPR-Cas system, optionally a CRISPR-Cas system based therapy or therapeutic in a population, comprising (a) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, and from said selected target sites subselecting target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, or (b) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, or selecting for a (therapeutic) locus of interest gRNA target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, and optionally estimating the number of (sub)selected target sites needed to treat or otherwise modulate or manipulate a population, optionally validating one or more of the (sub)selected target sites for an individual subject, optionally designing one or more gRNA recognizing one or more of said (sub)selected target sites.

In an aspect, the invention relates to a method for developing or designing a gRNA for use in a CRISPR-Cas system, optionally a CRISPR-Cas system based therapy or therapeutic in a population, comprising (a) selecting for a locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, and from said selected target sites subselecting target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, or (b) selecting for a (therapeutic) locus of interest gRNA target sites, wherein said target sites have minimal sequence variation across a population, or selecting for a (therapeutic) locus of interest gRNA target sites, wherein a gRNA directed against said target sites recognizes a minimal number of off-target sites across said population, and optionally estimating the number of (sub)selected target sites needed to treat or otherwise modulate or manipulate a population, optionally validating one or more of the (sub)selected target sites for an individual subject, optionally designing one or more gRNA recognizing one or more of said (sub)selected target sites.

In a further aspect, the invention relates to method for developing or designing a CRISPR-Cas system, such as a CRISPR-Cas system based therapy or therapeutic, optionally in a population; or for developing or designing a gRNA for use in a CRISPR-Cas system, optionally a CRISPR-Cas system based therapy or therapeutic, optionally in a population, comprising: selecting a set of target sequences for one or more loci in a target population, wherein the target sequences do not contain variants occurring above a threshold allele frequency in the target population (i.e. platinum target sequences); removing from said selected (platinum) target sequences any target sequences having high frequency off-target candidates (relative to other (platinum) targets in the set) to define a final target sequence set; preparing one or more, such as a set of CRISPR-Cas systems based on the final target sequence set, optionally wherein a number of CRISP-Cas systems prepared is based (at least in part) on the size of a target population.

In certain embodiments, off-target candidates/off-targets, PAM restrictiveness, target cleavage efficiency, or effector protein specificity is identified or determined using a sequencing-based double-strand break (DSB) detection assay, such as described herein elsewhere. In certain embodiments, off-target candidates/off-targets are identified or determined using a sequencing-based double-strand break (DSB) detection assay, such as described herein elsewhere. In certain embodiments, off-targets, or off target candidates have at least 1, preferably 1-3, mismatches or (distal) PAM mismatches, such as 1 or more, such as 1, 2, 3, or more (distal) PAM mismatches. In certain embodiments, sequencing-based DSB detection assay comprises labeling a site of a DSB with an adapter comprising a primer binding site, labeling a site of a DSB with a barcode or unique molecular identifier, or combination thereof, as described herein elsewhere.

It will be understood that the guide sequence of the gRNA is 100% complementary to the target site, i.e. does not comprise any mismatch with the target site. It will be further understood that “recognition” of an (off-)target site by a gRNA presupposes CRISPR-Cas system functionality, i.e. an (off-)target site is only recognized by a gRNA if binding of the gRNA to the (off-)target site leads to CRISPR-Cas system activity (such as induction of single or double strand DNA cleavage, transcriptional modulation, etc).

In certain embodiments, the target sites having minimal sequence variation across a population are characterized by absence of sequence variation in at least 99%, preferably at least 99.9%, more preferably at least 99.99% of the population. In certain embodiments, optimizing target location comprises selecting target sequences or loci having an absence of sequence variation in at least 99%, %, preferably at least 99.9%, more preferably at least 99.99% of a population. These targets are referred to herein elsewhere also as “platinum targets”. In certain embodiments, said population comprises at least 1000 individuals, such as at least 5000 individuals, such as at least 10000 individuals, such as at least 50000 individuals.

In certain embodiments, the off-target sites are characterized by at least one mismatch between the off-target site and the gRNA. In certain embodiments, the off-target sites are characterized by at most five, preferably at most four, more preferably at most three mismatches between the off-target site and the gRNA. In certain embodiments, the off-target sites are characterized by at least one mismatch between the off-target site and the gRNA and by at most five, preferably at most four, more preferably at most three mismatches between the off-target site and the gRNA.

In certain embodiments, said minimal number of off-target sites across said population is determined for high-frequency haplotypes in said population. In certain embodiments, said minimal number of off-target sites across said population is determined for high-frequency haplotypes of the off-target site locus in said population. In certain embodiments, said minimal number of off-target sites across said population is determined for high-frequency haplotypes of the target site locus in said population. In certain embodiments, the high-frequency haplotypes are characterized by occurrence in at least 0.1% of the population.

In certain embodiments, the number of (sub)selected target sites needed to treat a population is estimated based on based low frequency sequence variation, such as low frequency sequence variation captured in large scale sequencing datasets. In certain embodiments, the number of (sub)selected target sites needed to treat a population of a given size is estimated.

In certain embodiments, the method further comprises obtaining genome sequencing data of a subject to be treated; and treating the subject with a CRISPR-Cas system selected from the set of CRISPR-Cas systems, wherein the CRISPR-Cas system selected is based (at least in part) on the genome sequencing data of the individual.

In certain embodiments, the ((sub)selected) target is validated by genome sequencing, preferably whole genome sequencing.

In certain embodiments, target sequences or loci as described herein are (further) selected based on optimization of one or more parameters consisting of; PAM type (natural or modified), PAM nucleotide content, PAM length, target sequence length, PAM restrictiveness, target cleavage efficiency, and target sequence position within a gene, a locus or other genomic region.

In certain embodiments, target sequences or loci as described herein are (further) selected based on optimization of one or more of target loci location, target length, target specificity, and PAM characteristics. As used herein, PAM characteristics may comprise for instance PAM sequence, PAM length, and/or PAM GC contents. In certain embodiments, optimizing PAM characteristics comprises optimizing nucleotide content of a PAM. In certain embodiments, optimizing nucleotide content of PAM is selecting a PAM with a motif that maximizes abundance in the one or more target loci, minimizes mutation frequency, or both. Minimizing mutation frequency can for instance be achieved by selecting PAM sequences devoid of or having low or minimal CpG.

In certain embodiments, the effector protein for each CRISPR-Cas system in the set of CRISPR-Cas systems is selected based on optimization of one or more parameters selected from the group consisting of; effector protein size, ability of effector protein to access regions of high chromatin accessibility, degree of uniform enzyme activity across genomic targets, epigenetic tolerance, mismatch/budge tolerance, effector protein specificity, effector protein stability or half-life, effector protein immunogenicity or toxicity.

In certain embodiments, optimizing target (sequence) length comprises selecting a target sequence within one or more target loci between 5 and 25 nucleotides. In certain embodiments, a target sequence is 20 nucleotides.

In certain embodiments, optimizing target specificity comprises selecting targets loci that minimize off-target candidates.

In certain embodiments, the gRNA is a tru gRNA, an escorted gRNA, or a protected gRNA.

It will be understood that the CRISPR-Cas systems according to the invention as described herein, such as the CRISPR-Cas systems for use in the methods according to the invention as described herein, may be suitably used for any type of application known for CRISPR-Cas systems, preferably in eukaryotes. In certain aspects, the application is therapeutic, preferably therapeutic in a eukaryote organism, such as including but not limited to animals (including human), plants, algae, fungi (including yeasts), etc. Alternatively, or in addition, in certain aspects, the application may involve accomplishing or inducing one or more particular traits or characteristics, such as genotypic and/or phenotypic traits or characteristics, as also described herein elsewhere.

For the invention described herein, the following criteria may be taken into account when optimizing the respective parameters or variables.

CRISPR Effector Choice

1. Size:

Currently, CRISPR single nuclease effectors demonstrating high efficiency mammalian genome editing range from 1053 amino acids (SaCas9) to 1368 amino acids (SpCas9), (AsCpf1, 1307aa; and LbCpf1, 1246). While smaller orthologs of Cas9 do exist and cleave DNA with high efficiency in vitro, Cas9 orthologs smaller than SaCas9 have shown diminished mammalian DNA cleavage efficiency. The large size of current single effector CRISPR nucleases is challenging for both nanoparticle protein delivery and viral vector delivery strategies. For protein delivery, payload per particle is a function of 3-D protein size, and for viral delivery of single effectors, large gene size limits flexibility for multiplexing or use of large cell-type specific promoters. Considerations relating to delivery are described detailed further herein below.

2. Protein Search:

The ability of the CRISPR effector to access regions of high chromatin complexity can be viewed in two ways 1) this increases the versatility of the CRISPR effector as a tool for genome editing or 2) this may be undesirable due to cellular dysregulation resulting from perturbation of the genomic structure of cells contacted with the CRISPR effector. There have been reports that the most active Cas9 guides are ones that target low nucleosomal occupancy positions: elifesciences.orgicontent/5/e12677, and elifesciences.orgicontent/5/e13450; however, over a longer time scale, cleavage can still occur (also cleavage can occur during replication when the nucleosomal occupancy is moved) Considerations relating to choice of Cpf1 and modifications thereof are described detailed further herein below.

3. Efficacy:

Overall efficiency: robust and uniform enzyme activity across genomic targets in regions of open chromatin is generally desirable for all single effector nucleases. On the other hand, robust and uniform enzyme activity across genomic targets with varying chromatin complexity and epigenetic marks may not be desirable for research and therapeutic applications. It has been shown that Cas9 shows robust cleavage of methylated DNA, and this increases the utility of the enzyme. On the other hand, CRISPR effector binding or cleavage at loci enriched for epigenetic marks may dysregulate cellular processes. A further aspect to be considered is whether enzymes that do not disturb chromatin structure are desirable. If cleaving a locus in a terminally differentiated cell, it may be desirable to utilize enzymes that are not capable of penetrating silenced regions of the genome. Alternatively, when cleaving a locus in a precursor of a differentiated cell type, then it may be advantageous to be able to penetrate regions of the genome inactive at the time of editing.

4. Specificity: Mismatch/Bulge Tolerance:

Naturally occurring Cas9 orthologs: naturally occurring CRISPR effectors show tolerance of mismatches or bulges between the RNA guide and DNA target. This tolerance is generally undesirable for therapeutic applications. For therapeutic applications, patients should be individually screened for perfect target guide RNA complementarity, and tolerance of bulges and mismatches will only increase the likelihood of off-target DNA cleavage. High specificity engineered variants have been developed, such as eSpCas9 and Cas9-HF1 for Cas9; these variants show decreased tolerance of mismatches between DNA targets and the RNA guide (relevant to mismatches in approximately the PAM distal 12-14 nucleotides of the guide RNA given 20nt of guide RNA target complementarity).

5. PAM Choice:

Natural PAM vs. Modified PAM: Targets for each single effector CRISPR DNA endonuclease discovered so far require a protospacer adjacent motif (PAM) flanking the guide RNA complimentary region of the target. For the DNA endonucleases discovered so far, the PAM motifs have at least 2 nucleotides of specificity, such as 2, 3, 4, 5 or more nucleotides of specificity, such as 2-4 or 2-5 nucleotides of specificity, which curtails the fraction of possible targets in the genome that can be cleaved with a single natural enzyme. Mutation of naturally occurring DNA endonucleases has resulted in protein variants with modified PAM specificities. Cumulatively, the more such variants exist for a given protein targeting different PAMs, the greater the density of genomic targets are available for use in therapeutic design (See population efficacy). Nucleotide content: Nucleotide content of PAMs can affect what fraction of the genome can be targeted with an individual protein due to differences in the abundance of a particular motif in the genome or in a specific therapeutic locus of the genome. Additionally, nucleotide content can affect PAM mutation frequencies in the genome (See population efficacy). Cpf1 proteins with altered PAM specificity can address this issue (as described further herein). Influence of PAM length/complexity on target specificity: Cas9 interrogates the genome by first binding to a PAM site before attempting to create a stable RNA/DNA duplex by melting the double stranded DNA. Since the complexity of the PAM limits the possible space of targets interrogated, a more complex PAM will have fewer possible sites at which off-target cleavage can occur.

6. crRNA Processing Capabilities of the Enzyme: Multiplexing:

For multiplexing, crRNA processing capabilities are desirable, as a transcript expressed from a single promoter can contain multiple different crRNAs. This transcript is then processed into multiple constituent crRNAs by the protein, and multiplexed editing proceeds for each target specified by the crRNA. On the other hand, the rules for RNA endonucleolytic processing of multi crRNA transcripts into crRNAs are not fully understood. Hence, for therapeutic applications, crRNA processing may be undesirable due to off-target cleavage of endogenous RNA transcripts.

Target Choice

1. Target Length:

Although most protospacer elements observed in naturally occurring Cas9 and Cpf1 CRISPR arrays are longer than 20nt, protospacer complimentary regions of resulting crRNA products are often processed to 20nt (Cas9) or do not confer specificity beyond 20nt (Cpf1). Extension of the target complimentary region of the guide RNA beyond 20nt likely is positioned outside of the footprint of the protein on the guide RNA and is often processed away by exonucleases (See protected guide RNAs for further discussion).

2. Efficiency Screening:

Screening for CRISPR effector efficacy has been performed by studying the efficacy of knockdown of cell surface proteins using different DNA targets. These studies show some evidence that position dependent nucleotide content in CRISPR effector targets and flanking nucleotides affects the efficacy of target cleavage.

3. Specificity Screening:

Unbiased investigation of genome-wide CRISPR nuclease activity suggests that most off-target activity occurs at loci with at most three mismatches to the RNA guide. Current approaches for CRISPR effector target selection rank off-target candidates found in the reference human genome by both the number and position of RNA guide mismatches, with the assumption that loci containing less than 3 mismatches or containing PAM distal mismatches are more likely to be cleaved. However, in a population of individuals, this strategy is complicated by the existence of multiple haplotypes (sets of associated variants), which will contain different positions or numbers of mismatches at candidate off-target sites (See: population safety).

Guide RNA Design

Several technologies have been developed to address different aspects of efficacy and specificity.

1. Tru Guide:

Trimming 1-3 nt off from the 3′ end of the target complimentary region of the gRNA often decreases activity at off-target loci containing at least one mismatch to the guide RNA. Likely, with fewer nucleotides of base-pairing between the off-target and gRNA, each mismatch has a greater thermodynamic consequence to the stability of the CRISPR effector-gRNA complex with the off-target DNA. Percentage of successfully cleaved targets may be reduced in using tru guides: i.e., some sites that worked with a 20nt guide may not cut efficiently with a 17nt guide; but the ones that do work with 17nt generally cleavage as efficiently.

2. Protected Guide:

Protected guides utilize an extended guide RNA and/or trans RNA/DNA elements to 1) create stable structures in the sgRNA that compete with sgRNA base-pairing at a target or off-target site or 2) (optionally) extend complimentary nucleotides between the gRNA and target. For extended RNA implementations, secondary structure results from complementarity between the 3′ extension of the guide RNA and another target complimentary region of the guide RNA. For trans implementations, DNA or RNA elements bind the extended or normal length guide RNA partially obscuring the target complimentary region of the sgRNA.

Dosage

The dosage of the CRISPR components should take into account the following factors.

1. Target Search:

CRISPR effector/guide RNA-enzyme complexes use 3-D stochastic search to locate targets. Given equal genomic accessibility, the probability of the complex finding an off-target or on-target is similar.

2. Binding (Target Dwell Time):

Once located, the binding kinetics of the complex at an on-target or an off-target with few mismatches differs only slightly. Hence, target search and binding are likely not the rate-limiting steps for DNA cleavage at on-target or off-target loci. ChIP data suggests that complex dwell time does decrease accompanying increasing mismatches between the off-target locus and RNA guide, particularly in the PAM-proximal ‘seed’ region of the RNA guide.

3. Cutting (Thermodynamic Barrier to Assuming an Active Conformation):

A major rate-limiting step for CRISPR effector enzymatic activity appears to be configuration of the target DNA and guide RNA-protein complex in an active conformation for DNA cleavage. Increasing mismatches at off-target loci decrease the likelihood of the complex achieving an active conformation at off-target loci.

The difference between binding and cutting is why ChIP has very low predictive power as a tool for evaluating the off-target cleavage of Cpf1.

If the probability of finding an off-target or on-target is similar, then the difference in rate of on and off-target cleavage is likely due to the fact that the probability of cleavage at on target sites is greater than off target sites. (See temporal control) The stochastic search means that Cpf1 suggests that an incorrect model is to view Cpf1 as preferentially cleaving the on-target site first and only moving onto off-target sites after on-target cleavage is saturated; instead, all sites are interrogated at random, and the probability of progression to cutting after PAM binding is what differentiates the propensity of on vs. off-target cutting.

4. Repetition in DNA Modification at an Individual Locus:

NHEJ repair of DNA double strand breaks is generally high fidelity (Should find exact error rate). Hence, it is likely that a nuclease must cut an individual locus many times before an error in NHEJ results in an indel at the cut site. The probability of observing an indel is the compounding probability of observing a double strand break based on 1) target search probability, 2) target dwell time, and 3) overcoming the thermodynamic barrier to DNA cleavage.

5. Enzyme Concentration:

Even at very low concentrations, search may still encounter an off-target prior to an on-target. Thereafter, the number and location of mismatches in an off-target, and likely the nucleotide content of the target will influence the likelihood of DNA cleavage.

Thinking about on/off target cleavage in probabilistic terms, each interaction that Cas9 or Cpf1 has with the genome can be thought of as having some probability of successful cleavage. Reducing the dose will reduce the number of effector molecules available for interacting with the genome, and thus will limit the additive probability of repeated interactions at off-target sites.

Temporal and Spatial Control of the CRISPR System

Various technologies have been developed which provide additional options for addressing efficacy, specificity and safety issues. More particularly these options can be used to allow for temporal control. More particularly these technologies allow for temporal/spatial control (as described further herein):

1. Double nickases

2. Escorted guides

3. Split-effector protein

4. “self-inactivating” systems or “governing guides”

In the following, the different variables and how they influence the design of a CRISPR-based editing system are described in more detail.

Specificity—Select Most Specific Guide RNA

a. Guide Specificity

While early reports were fairly contradictory on the ability to accurately predict guide RNAs with limited off-target activity, statistical analysis based on a large number of data has made it possible to identify rules governing off-target effects. Doench et al. (Nat Biotechnol. 2016 February; 34(2):184-91) describe the profiling of the off-target activity of thousands of sgRNAs and the development of a metric to predict off-target sites.

Accordingly, in particular embodiments, the methods of the invention involve selecting a guide RNA which, based on statistical analysis, is less likely to generate off-target effects.

b. Guide Complementarity

It is generally envisaged that the degree of complementarity between a guide sequence and its corresponding target sequence should be as high as possible, such as more than about 50%, 60%, 75%, 80%, 85%, 90%, 95%, 97.5%, 99%, or 100%. However, in particular embodiments, a particular concern is reducing off-target interactions, e.g., reducing the guide interacting with a target sequence having low complementarity. It has been shown that certain mutations result in the CRISPR-Cas system being able to distinguish between target and off-target sequences that have greater than 80% to about 95% complementarity, e.g., 83%-84% or 88-89% or 94-95% complementarity (for instance, distinguishing between a target having 18 nucleotides from an off-target of 18 nucleotides having 1, 2 or 3 mismatches). Accordingly, in particular embodiments, the guide is selected such that the degree of complementarity between a guide sequence and its corresponding target sequence is greater than 94.5% or 95% or 95.5% or 96% or 96.5% or 97% or 97.5% or 98% or 98.5% or 99% or 99.5% or 99.9%, or 100%. Off target is less than 100% or 99.9% or 99.5% or 99% or 99% or 98.5% or 98% or 97.5% or 97% or 96.5% or 96% or 95.5% or 95% or 94.5% or 94% or 93% or 92% or 91% or 90% or 89% or 88% or 87% or 86% or 85% or 84% or 83% or 82% or 81% or 80% complementarity between the sequence and the guide, with it advantageous that off target is 100% or 99.9% or 99.5% or 99% or 99% or 98.5% or 98% or 97.5% or 97% or 96.5% or 96% or 95.5% or 95% or 94.5% complementarity between the sequence and the guide.

c. Select Guide/Enzyme Concentration

For minimization of toxicity and off-target effect, it will be important to control the concentration of Cpf1 protein and guide RNA delivered. Optimal concentrations of Cpf1 protein and guide RNA can be determined by testing different concentrations in a cellular or non-human eukaryote animal model and using deep sequencing the analyze the extent of modification at potential off-target genomic loci. For example, for the guide sequence targeting 5′-GAGTCCGAGCAGAAGAAGAA-3′ (SEQ ID NO: 23) in the EMX1 gene of the human genome, deep sequencing can be used to assess the level of modification at the following two off-target loci, 1: 5′-GAGTCCTAGCAGGAGAAGAA-3′ (SEQ ID NO: 24) and 2: 5′-GAGTCTAAGCAGAAGAAGAA-3′ (SEQ ID NO: 25). The concentration that gives the highest level of on-target modification while minimizing the level of off-target modification should be chosen for in vivo delivery.

Specificity—Select Most Specific Enzyme

a. Enzyme Modifications to Enhance Specificity

In particular embodiments, a reduction of off-target cleavage is ensured by destabilizing strand separation, more particularly by introducing mutations in the Cpf1 enzyme decreasing the positive charge in the DNA interacting regions (as described herein and further exemplified for Cas9 by Slaymaker et al. 2016 (Science, 1; 351(6268):84-8). In further embodiments, a reduction of off-target cleavage is ensured by introducing mutations into Cpf1 enzyme which affect the interaction between the target strand and the guide RNA sequence, more particularly disrupting interactions between Cpf1 and the phosphate backbone of the target DNA strand in such a way as to retain target specific activity but reduce off-target activity (as described for Cas9 by Kleinstiver et al. 2016, Nature, 28; 529(7587):490-5). In particular embodiments, the off-target activity is reduced by way of a modified Cpf1 wherein both interaction with target strand and non-target strand are modified compared to wild-type Cpf1.

The methods and mutations which can be employed in various combinations to increase or decrease activity and/or specificity of on-target vs. off-target activity, or increase or decrease binding and/or specificity of on-target vs. off-target binding, can be used to compensate or enhance mutations or modifications made to promote other effects. Such mutations or modifications made to promote other effects include mutations or modification to the Cpf1 effector protein and/or mutation or modification made to a guide RNA.

With a similar strategy used to improve Cas9 specificity (Slaymaker et al. 2015 “Rationally engineered Cas9 nucleases with improved specificity”), specificity of Cpf1 can be improved by mutating residues that stabilize the non-targeted DNA strand. This may be accomplished without a crystal structure by using linear structure alignments to predict 1) which domain of Cpf1 binds to which strand of DNA and 2) which residues within these domains contact DNA.

However, this approach may be limited due to poor conservation of Cpf1 with known proteins. Thus it may be desirable to probe the function of all likely DNA interacting amino acids (lysine, histidine and arginine).

Positively charged residues in the RuvC domain are more conserved throughout Cpf1s than those in the Rad50 domain indicating that RuvC residues are less evolutionarily flexible. This suggests that rigid control of nucleic acid binding is needed in this domain (relative to the Rad50 domain). Therefore, it is possible this domain cuts the targeted DNA strand because of the requirement for RNA:DNA duplex stabilization (precedent in Cas9). Furthermore, more arginines are present in the RuvC domain (5% of RuvC residues 904 to 1307 vs 3.8% in the proposed Rad50 domains) suggesting again that RuvC targets one of the DNA strands. Arginines are more involved in binding nucleic acid major and minor grooves (Rohs Nature 2009: rohslab.cmb.usc.edu/Papers/Rohs_etal_Nature.pdf). Major/minor grooves would only be present in a duplex (such as DNA:RNA targeting duplex), further suggesting that RuvC may be involved in cutting.

Based on the structural analysis of the RuvC and Rad50 domains, it can be deduced what the relevant domains look like in Cpf1, and infer which regions and residues may contact DNA. Accordingly, in certain embodiments the Cpf1 enzyme is modified by mutation of one or more residues (in the RuvC domain) including but not limited positions R909, R912, R930, R947, K949, R951, R955, K965, K968, K1000, K1002, R1003, K1009, K1017, K1022, K1029, K1035, K1054, K1072, K1086, R1094, K1095, K1109, K1118, K1142, K1150, K1158, K1159, R1220, R1226, R1242, and/or R1252 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6). Additionally or alternatively, in certain embodiments, the Cpf1 enzyme is modified by mutation of one or more residues (in the RAD50) domain including but not limited positions K324, K335, K337, R331, K369, K370, R386, R392, R393, K400, K404, K406, K408, K414, K429, K436, K438, K459, K460, K464, R670, K675, R681, K686, K689, R699, K705, R725, K729, K739, K748, and/or K752 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6).

From these specific observations about AsCpf1 similar residues can be identified in Cpf1 from other species by sequence alignments. In certain embodiments, the Cpf1 enzyme is modified by mutation of one or more residues including but not limited positions R912, T923, R947, K949, R951, R955, K965, K968, K1000, R1003, K1009, K1017, K1022, K1029, K1072, K1086, F1103, R1226, and/or R1252 with reference to amino acid position numbering of AsCpf1 ( Acidaminococcus sp. BV3L6). In certain embodiments, the enzyme is modified by mutation of one or more residues including but not limited positions R833, R836, K847, K879, K881, R883, R887, K897, K900, K932, R935, K940, K948, K953, K960, K984, K1003, K1017, R1033, R1138, R1165, and/or R1252 with reference to amino acid position numbering of LbCpf1 ( Lachnospiraceae bacterium ND2006).

b. Selecting Suitable PAM Recognition

The requirement of a protospacer adjacent motif (PAM) of most CRISPR effector proteins, ensures another level of specificity in that only the target which is preceded by the relevant motif for the enzyme, will be cleaved. Thus, in particular embodiments, where available it may be of interest to select an effector protein with a stringent PAM so as to reduce off-target effects. Such an effector protein may be a Cpf1 ortholog or an effector protein having altered specificity.

On the other hand, the use of a Cpf1 effector protein can be limited by its protospacer adjacent motif (PAM), in that it will only be able to robustly cleave target sites preceded by said motif. For instance, the Acidaminococcus sp. BV3L6 Cpf1 (AsCpf1), which has been successfully harnessed for genome editing can only cleave target sites precede by a TTTV protospacer adjacent motif (PAM), which limits its practical utility. Where broad applicability is desirable or required for multiplexing, the selection of an effector protein with a different PAM specificity may be of interest. Again, this altered specificity may be found in a Cpf1 ortholog. However, it has been found that the Cpf1 effector protein can be mutated to modify its PAM specificity.

Modification of PAM specificity has been performed by a structure-guided saturation mutagenesis screen to increase the targeting range of Cpf1 (Linyi et al. 2016, BioRxiv, dx.doi.org/10.1101/091611). Two variants of AsCpf1 were engineered with the mutations S542R/K607R and S542R/K548V/N552R that can cleave target sites with TYCV/CCCC and TATV PAMs, respectively, with enhanced activities in vitro and in human cells. Genome-wide assessment of off-target activity indicated that these variants retain a high level of DNA targeting specificity. It was found that by the provision of the additional AsCpf1 effector protein variants, this results in the addition of one cleavage site for every ˜8.7 bp in non-repetitive regions of the human genome.

Further Cpf1 mutants are also envisaged herein. In particular embodiments, a mutated Cpf1 is used wherein said mutated Cpf1 comprises one or more mutated amino acid residue at position 11, 12, 13, 14, 15, 16, 17, 34, 36, 39, 40, 43, 46, 47, 50, 54, 57, 58, 111, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 532, 533, 534, 535, 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574, 575, 592, 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 616, 617, 618, 619, 620, 626, 627, 628, 629, 630, 631, 632, 633, 634, 635, 636, 637, 638, 642, 643, 644, 645, 646, 647, 648, 649, 651, 652, 653, 654, 655, 656, 676, 679, 680, 682, 683, 684, 685, 686, 687, 688, 689, 690, 691, 692, 693, 707, 711, 714, 715, 716, 717, 718, 719, 720, 721, 722, 739, 765, 768, 769, 773, 777, 778, 779, 780, 781, 782, 783, 784, 785, 786, 871, 872, 873, 874, 875, 876, 877, 878, 879, 880, 881, 882, 883, 884, or 1048; preferably, one or more mutated amino acid residue at position 130, 131, 132, 133, 134, 135, 136, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550, 551, 552, 570, 571, 572, 573, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609, 610, 611, 612, 613, 614, 615, 630, 631, 632, 646, 647, 648, 649, 650, 651, 652, 653, 683, 684, 685, 686, 687, 688, 689, or 690; more preferably one or more mutated amino acid residue at position 539, 542, 547, 548, 550, 551, 552, 167, 604, and/or 607 of AsCpf1, or the corresponding position of an AsCpf1 orthologue, homologue, or variant, preferably mutated amino acid residues at positions 542 or 542 and 607, wherein said mutations preferably are 542R and 607R, such as S542R and K607R; or preferably mutated amino acid residues at positions 542 and 548 (and optionally 552), wherein said mutations preferably are 542R and 548V (and optionally 552R), such as S542R and K548V (and optionally N552R); or at position 532, 538, 542, and/or 595 of LbCpf1, or the corresponding position of an AsCpf1 orthologue, homologue, or variant, preferably mutated amino acid residues at positions 532 or 532 and 595, wherein said mutations preferably are 532R and 595R, such as G532R and K595R; or preferably mutated amino acid residues at positions 532 and 538 (and optionally 542), wherein said mutations preferably are 532R and 538V (and optionally 542R), such as G532R and K538V (and optionally Y542R).

Accordingly, these variants increase the targeting range, providing a useful addition to the CRISPR/Cas genome engineering toolbox. At the same time, the provision of Cpf1 effector proteins with alternative PAM specificity allows for the selection of a particular variant with optimal specificity for a particular target sequence.

System Approaches to Reduce Off-Target Effects:

a. Double Nickase

Alternatively, to minimize the level of toxicity and off-target effect, a Cpf1 nickase can be used with a pair of guide RNAs targeting a site of interest. Guide sequences and strategies to minimize toxicity and off-target effects can be as in WO 2014/093622 (PCT/US2013/074667); or, via mutation as described herein.

The invention thus contemplates methods of using two or more nickases, in particular a dual or double nickase approach. In some aspects and embodiments, a single type FnCpf1, AsCpf1 or LbCpf1 nickase may be delivered, for example a modified FnCpf1, AsCpf1 or LbCpf1 or a modified FnCpf1, AsCpf1 or LbCpf1 nickase as described herein. This results in the target DNA being bound by two FnCpf1 nickases. In addition, it is also envisaged that different orthologs may be used, e.g., an FnCpf1, AsCpf1 or LbCpf1 nickase on one strand (e.g., the coding strand) of the DNA and an ortholog on the non-coding or opposite DNA strand. The ortholog can be, but is not limited to, a Cpf1 nickase such as a AsCpf1 nickase or a LbCpf1 nickase or FnCpf1 nickase. It may be advantageous to use two different orthologs that require different PAMs and may also have different guide requirements, thus allowing a greater deal of control for the user. In certain embodiments, DNA cleavage will involve at least four types of nickases, wherein each type is guided to a different sequence of target DNA, wherein each pair introduces a first nick into one DNA strand and the second introduces a nick into the second DNA strand. In such methods, at least two pairs of single stranded breaks are introduced into the target DNA wherein upon introduction of first and second pairs of single-strand breaks, target sequences between the first and second pairs of single-strand breaks are excised. In certain embodiments, one or both of the orthologs is controllable, i.e. inducible.

b. Escorted Guides

The methods provided herein may also involve the use of escorted Cpf1 CRISPR-Cas systems or complexes, especially such a system involving an escorted Cpf1 CRISPR-Cas system guide. By “escorted” is meant that the Cpf1 CRISPR-Cas system or complex or guide is delivered to a selected time or place within a cell, so that activity of the Cpf1 CRISPR-Cas system or complex or guide is spatially or temporally controlled. For example, the activity and destination of the Cpf1 CRISPR-Cas system or complex or guide may be controlled by an escort RNA aptamer sequence that has binding affinity for an aptamer ligand, such as a cell surface protein or other localized cellular component. Alternatively, the escort aptamer may for example be responsive to an aptamer effector on or in the cell, such as a transient effector, such as an external energy source that is applied to the cell at a particular time. The principle of escorted guides and embodiments thereof are described in detail in WO2016094874 incorporated by reference herein.

Aptamers are biomolecules that can be designed or selected to bind tightly to other ligands, for example using a technique called systematic evolution of ligands by exponential enrichment (SELEX; Tuerk C, Gold L: “Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase.” Science 1990, 249:505-510). Nucleic acid aptamers can for example be selected from pools of random-sequence oligonucleotides, with high binding affinities and specificities for a wide range of biomedically relevant targets, suggesting a wide range of therapeutic utilities for aptamers (Keefe, Anthony D., Supriya Pai, and Andrew Ellington. “Aptamers as therapeutics.” Nature Reviews Drug Discovery 9.7 (2010): 537-550). These characteristics also suggest a wide range of uses for aptamers as drug delivery vehicles (Levy-Nissenbaum, Etgar, et al. “Nanotechnology and aptamers: applications in drug delivery.” Trends in biotechnology 26.8 (2008): 442-449; and, Hicke B J, Stephens A W. “Escort aptamers: a delivery service for diagnosis and therapy.” J Clin Invest 2000, 106:923-928.). Aptamers may also be constructed that function as molecular switches, responding to a que by changing properties, such as RNA aptamers that bind fluorophores to mimic the activity of green fluorescent protein (Paige, Jeremy S., Karen Y. Wu, and Samie R. Jaffrey. “RNA mimics of green fluorescent protein.” Science 333.6042 (2011): 642-646). It has also been suggested that aptamers may be used as components of targeted siRNA therapeutic delivery systems, for example targeting cell surface proteins (Zhou, Jiehua, and John J. Rossi. “Aptamer-targeted cell-specific RNA interference.” Silence 1.1 (2010): 4). The aptamers used in this aspect are designed to improve gRNA delivery, including delivery across the cellular membrane, to intracellular compartments, or into the nucleus. Such a structure can include, either in addition to the one or more aptamer(s) or without such one or more aptamer(s), moiety(ies) so as to render the guide deliverable, inducible or responsive to a selected effector. In particular embodiments, a gRNA is designed that responds to normal or pathological physiological conditions, including without limitation pH, hypoxia, O2 concentration, temperature, protein concentration, enzymatic concentration, lipid structure, light exposure, mechanical disruption (e.g. ultrasound waves), magnetic fields, electric fields, or electromagnetic radiation. Accordingly, in particular embodiments, the escort aptamer has binding affinity for an aptamer ligand on or in the cell, or the escort aptamer is responsive to a localized aptamer effector on or in the cell, wherein the presence of the aptamer ligand or effector on or in the cell is spatially or temporally restricted.

Once intended alterations have been introduced, such as by editing intended copies of a gene in the genome of a cell, continued CRISPR/Cpf1 expression in that cell is no longer necessary. Indeed, sustained expression would be undesirable in certain cases in case of off-target effects at unintended genomic sites, etc. Thus time-limited expression is of interest.

Inducible expression offers one approach, but in addition Applicants have engineered a self-inactivating Cpf1 CRISPR-Cas system that relies on the use of a non-coding guide target sequence within the CRISPR vector itself Thus, after expression begins, the CRISPR system will lead to its own destruction, but before destruction is complete it will have time to edit the genomic copies of the target gene (which, with a normal point mutation in a diploid cell, requires at most two edits). Simply, the self-inactivating Cpf1 CRISPR-Cas system includes additional RNA (i.e., guide RNA) that targets the coding sequence for the CRISPR enzyme itself or that targets one or more non-coding guide target sequences complementary to unique sequences present in one or more of the following: (a) within the promoter driving expression of the non-coding RNA elements, (b) within the promoter driving expression of the Cpf1 gene, (c) within 100 bp of the ATG translational start codon in the Cpf1 coding sequence, (d) within the inverted terminal repeat (iTR) of a viral delivery vector, e.g., in an AAV genome.

Examples of inducible systems are light responsive systems. Light responsiveness of an inducible system are achieved via the activation and binding of cryptochrome-2 and CIB1. Blue light stimulation induces an activating conformational change in cryptochrome-2, resulting in recruitment of its binding partner CIB1. This binding is fast and reversible, achieving saturation in <15 sec following pulsed stimulation and returning to baseline <15 min after the end of stimulation. These rapid binding kinetics result in a system temporally bound only by the speed of transcription/translation and transcript/protein degradation, rather than uptake and clearance of inducing agents. Cryptochrome-2 activation is also highly sensitive, allowing for the use of low light intensity stimulation and mitigating the risks of phototoxicity. Further, in a context such as the intact mammalian brain, variable light intensity may be used to control the size of a stimulated region, allowing for greater precision than vector delivery alone may offer.

In particular embodiments, energy sources such as electromagnetic radiation, sound energy or thermal energy can induce the guide. Advantageously, the electromagnetic radiation is a component of visible light. In a preferred embodiment, the light is a blue light with a wavelength of about 450 to about 495 nm. In an especially preferred embodiment, the wavelength is about 488 nm. In another preferred embodiment, the light stimulation is via pulses. The light power may range from about 0-9 mW/cm2. In a preferred embodiment, a stimulation paradigm of as low as 0.25 sec every 15 sec should result in maximal activation.

In particular embodiments, the system is chemically inducible. Exemplary designs of chemical inducible systems include: 1. ABI-PYL based system inducible by Abscisic Acid (ABA) (see, e.g., stke.sciencemag.org/cgi/content/abstract/sigtrans; 4/164/rs2), 2. FKBP-FRB based system inducible by rapamycin (or related chemicals based on rapamycin) (see, e.g., www.nature.com/nmeth/journal/v2/n6/full/nmeth763.html), 3. GID1-GAI based system inducible by Gibberellin (GA) (see, e.g., www.nature.com/nchembio/journal/v8/n5/full/nchembio.922.html). Another chemical inducible system is an estrogen receptor (ER) based system inducible by 4-hydroxytamoxifen (4OHT) (see, e.g., www.pnas.org/content/104/3/1027.abstract). A mutated ligand-binding domain of the estrogen receptor called ERT2 translocates into the nucleus of cells upon binding of 4-hydroxytamoxifen. In further embodiments of the invention any naturally occurring or engineered derivative of any nuclear receptor, thyroid hormone receptor, retinoic acid receptor, estrogen receptor, estrogen-related receptor, glucocorticoid receptor, progesterone receptor, androgen receptor may be used in inducible systems analogous to the ER based inducible system.

In particular embodiments, the chemical inducible system is based on change in sub-cellular localization. The polypeptide can include a DNA binding domain comprising at least five or more Transcription activator-like effector (TALE) monomers and at least one or more half-monomers specifically ordered to target the genomic locus of interest linked to at least one or more effector domains are further linker to a chemical or energy sensitive protein. This protein will lead to a change in the sub-cellular localization of the entire polypeptide (i.e. transportation of the entire polypeptide from cytoplasm into the nucleus of the cells) upon the binding of a chemical or energy transfer to the chemical or energy sensitive protein. This transportation of the entire polypeptide from one sub-cellular compartments or organelles, in which its activity is sequestered due to lack of substrate for the effector domain, into another one in which the substrate is present would allow the entire polypeptide to come in contact with its desired substrate (i.e. genomic DNA in the mammalian nucleus) and result in activation or repression of target gene expression.

Another inducible system is based on the design using Transient receptor potential (TRP) ion channel based system inducible by energy, heat or radio-wave (see, e.g., www.sciencemag.org/content/336/6081/604). These TRP family proteins respond to different stimuli, including light and heat. When this protein is activated by light or heat, the ion channel will open and allow the entering of ions such as calcium into the plasma membrane. This influx of ions will bind to intracellular ion interacting partners linked to a polypeptide including the guide and the other components of the Cpf1 CRISPR-Cas complex or system, and the binding will induce the change of sub-cellular localization of the polypeptide, leading to the entire polypeptide entering the nucleus of cells. Once inside the nucleus, the guide protein and the other components of the Cpf1 CRISPR-Cas complex will be active and modulating target gene expression in cells. This type of system could also be used to induce the cleavage of a genomic locus of interest in a cell; and, in this regard, it is noted that the Cpf1 enzyme is a nuclease. The light could be generated with a laser or other forms of energy sources. The heat could be generated by raise of temperature results from an energy source, or from nano-particles that release heat after absorbing energy from an energy source delivered in the form of radio-wave.

Photoinducibility provides the potential for spatial precision. Taking advantage of the development of optrode technology, a stimulating fiber optic lead may be placed in a precise brain region. Stimulation region size may then be tuned by light intensity. This may be done in conjunction with the delivery of the Cpf1 CRISPR-Cas system or complex of the invention, or, in the case of transgenic Cpf1 animals, guide RNA of the invention may be delivered and the optrode technology can allow for the modulation of gene expression in precise brain regions. A culture medium for culturing host cells includes a medium commonly used for tissue culture, such as M199-earle base, Eagle MEM (E-MEM), Dulbecco MEM (DMEM), SC-UCM102, UP-SFM (GIBCO BRL), EX-CELL302 (Nichirei), EX-CELL293-S (Nichirei), TFBM-01 (Nichirei), ASF104, among others. Suitable culture media for specific cell types may be found at the American Type Culture Collection (ATCC) or the European Collection of Authenticated Cell Cultures (ECACC). Culture media may be supplemented with amino acids such as L-glutamine, salts, anti-fungal or anti-bacterial agents such as Fungizone®, penicillin-streptomycin, animal serum, and the like. The cell culture medium may optionally be serum-free.

Temporal precision can also be achieved in vivo. This may be used to alter gene expression during a particular stage of development. This may be used to time a genetic cue to a particular experimental window. For example, genes implicated in learning may be overexpressed or repressed only during the learning stimulus in a precise region of the intact rodent or primate brain. Further, the invention may be used to induce gene expression changes only during particular stages of disease development. For example, an oncogene may be overexpressed only once a tumor reaches a particular size or metastatic stage. Conversely, proteins suspected in the development of Alzheimer's may be knocked down only at defined time points in the animal's life and within a particular brain region. Although these examples do not exhaustively list the potential applications of the invention, they highlight some of the areas in which the invention may be a powerful technology.

(c) Protected Guide RNAs

In one aspect, it is of interest to further enhance the specificity of Cpf1 given individual guide RNAs through thermodynamic tuning of the binding specificity of the guide RNA to target DNA. This is a general approach of introducing mismatches, elongation or truncation of the guide sequence to increase/decrease the number of complimentary bases vs. mismatched bases shared between a genomic target and its potential off-target loci, in order to give thermodynamic advantage to targeted genomic loci over genomic off-targets. Thus it can be of interest to modify the guide sequence by secondary structure to increase the specificity of the Cpf1 CRISPR-Cas system whereby the secondary structure can protect against exonuclease activity. This can be ensured by hybridizing a “protector RNA” to a guide sequence, wherein the “protector RNA” is an RNA strand complementary to the 5′ end of the guide RNA (gRNA), to thereby generate a partially double-stranded gRNA. Protecting the mismatched bases with a perfectly complementary protector sequence decreases the likelihood of target DNA binding to the mismatched base pairs at the 3′ end. In particular embodiments, additional sequences comprising an extended length may also be present. The principle of using protected guide RNAs is described in detail in WO/2016/094867, which is incorporated herein by reference.

Guide RNA (gRNA) extensions matching the genomic target provide gRNA protection and enhance specificity. Extension of the gRNA with matching sequence distal to the end of the spacer seed for individual genomic targets thus provides enhanced specificity. In particular embodiments, stable forms arise from protective states, where the extension forms a closed loop with the gRNA seed due to complimentary sequences in the spacer extension and the spacer seed. Thus, the protected guide concept also includes sequences matching the genomic target sequence distal of the 20mer spacer-binding region. Thermodynamic prediction can be used to predict completely matching or partially matching guide extensions that result in protected gRNA states as described in WO/2016/094867.

An extension sequence which corresponds to the extended length (ExL) may optionally be attached directly to the guide sequence at the 3′ end of the protected guide sequence. The extension sequence may be 2 to 12 nucleotides in length. Preferably ExL may be denoted as 0, 2, 4, 6, 8, 10 or 12 nucleotides in length. In a preferred embodiment the ExL is denoted as 0 or 4 nucleotides in length. In a more preferred embodiment the ExL is 4 nucleotides in length. The extension sequence may or may not be complementary to the target sequence. An extension sequence may further optionally be attached directly to the guide sequence at the 5′ end of the protected guide sequence as well as to the 3′ end of a protecting sequence. As a result, the extension sequence serves as a linking sequence between the protected sequence and the protecting sequence. Without wishing to be bound by theory, such a link may position the protecting sequence near the protected sequence for improved binding of the protecting sequence to the protected sequence.

(d) Formation of a RISC Through Guide Engineering

In some embodiments, the guide may be a protected guide (e.g. a pgRNA) or an escorted guide (e.g. an esgRNA) as described herein. Both of these, in some embodiments, make use of RISC. A RISC is a key component of RNAi. RISC (RNA-induced silencing complex) is a multiprotein, specifically a ribonucleoprotein, complex which incorporates one strand of a double-stranded RNA (dsRNA) fragment, such as small interfering RNA (siRNA) or microRNA (miRNA), which acts as a template for RISC to recognize a complementary messenger RNA (mRNA) transcript. The mRNA is thus cleaved by one of the components of the RISC.

As such, the formation of a RISC is advantageous in some embodiments. Guide RNAs according to various aspects of the present invention, including but not limited to protected and/or escorted guide RNAs, may be adapted to include RNA nucleotides that promote formation of a RISC, for example in combination with an siRNA or miRNA that may be provided or may, for instance, already be expressed in a cell. This may be useful, for instance, as a self-inactivating system to clear or degrade the guide.

Thus, the guide RNA may comprise a sequence complementary to a target miRNA or an siRNA, which may or may not be present within a cell. In this way, only when the miRNA or siRNA is present, for example through expression (by the cell or through human intervention), is there binding of the RNA sequence to the miRNA or siRNA which then results in cleavage of the guide RNA an RNA-induced silencing complex (RISC) within the cell. Therefore, in some embodiments, the guide RNA comprises an RNA sequence complementary to a target miRNA or siRNA, and binding of the guide RNA sequence to the target miRNA or siRNA results in cleavage of the guide RNA by an RNA-induced silencing complex (RISC) within the cell.

RISC formation through use of escorted guides is described in WO2016094874, RISC formation through use of protected guides is described in WO/2016/094867.

(e) Use of inducible Systems

In some embodiments, a CRISPR enzyme may form a component of an inducible system. The inducible nature of the system would allow for spatiotemporal control of gene editing or gene expression using a form of energy. The form of energy may include but is not limited to electromagnetic radiation, sound energy, chemical energy and thermal energy. Examples of inducible system include tetracycline inducible promoters (Tet-On or Tet-Off), small molecule two-hybrid transcription activations systems (FKBP, ABA, etc), or light inducible systems (Phytochrome, LOV domains, or cryptochrome). In one embodiment, the CRISPR enzyme may be a part of a Light Inducible Transcriptional Effector (LITE) to direct changes in transcriptional activity in a sequence-specific manner. The components of a light may include a CRISPR enzyme, a light-responsive cytochrome heterodimer (e.g. from Arabidopsis thaliana ), and a transcriptional activation/repression domain. Further examples of inducible DNA binding proteins and methods for their use are provided in U.S. 61/736,465 and U.S. 61/721,283, and WO 2014/018423 A2 which is hereby incorporated by reference in its entirety.

(f) Use of Inducible/Split Effector Enzymes

In an aspect the invention provides a (non-naturally occurring or engineered) inducible CRISPR protein according to the invention as described herein (CRISPR-Cas system), comprising: a first CRISPR protein fusion construct attached to a first half of an inducible dimer and a second CRISPR protein fusion construct attached to a second half of the inducible dimer, wherein the first Cpf1 fusion construct is operably linked to one or more nuclear localization signals, wherein the second CRISPR protein fusion construct is operably linked to one or more nuclear export signals, wherein contact with an inducer energy source brings the first and second halves of the inducible dimer together, wherein bringing the first and second halves of the inducible dimer together allows the first and second CRISPR protein fusion constructs to constitute a functional CRISPR protein (optionally wherein the CRISPR-Cas system comprises a guide RNA (gRNA) comprising a guide sequence capable of hybridizing to a target sequence in a genomic locus of interest in a cell, and wherein the functional CRISPR-Cas system binds to the target sequence and, optionally, edits the genomic locus to alter gene expression).

In an aspect of the invention in the inducible CRISPR-Cas system, the inducible dimer is or comprises or consists essentially of or consists of an inducible heterodimer. In an aspect, in inducible CRISPR-Cas system, the first half or a first portion or a first fragment of the inducible heterodimer is or comprises or consists of or consists essentially of an FKBP, optionally FKBP12. In an aspect of the invention, in the inducible CRISPR-Cas system, the second half or a second portion or a second fragment of the inducible heterodimer is or comprises or consists of or consists essentially of FRB. In an aspect of the invention, in the inducible CRISPR-Cas system, the arrangement of the first CRISPR fusion construct is or comprises or consists of or consists essentially of N′ terminal CRISPR part-FRB-NES. In an aspect of the invention, in the inducible CRISPR-Cas system, the arrangement of the first CRISP fusion construct is or comprises or consists of or consists essentially of NES-N′ terminal CRISP part-FRB-NES. In an aspect of the invention, in the inducible CRISPR-Cas system, the arrangement of the second CRISP fusion construct is or comprises or consists essentially of or consists of C′ terminal CRISP part-FKBP-NLS. In an aspect the invention provides in the inducible Cpf1 CRISPR-Cas system, the arrangement of the second CRISP fusion construct is or comprises or consists of or consists essentially of NLS-C′ terminal CRISP part-FKBP-NLS. In an aspect, in inducible CRISPR-Cas system there can be a linker that separates the CRISP part from the half or portion or fragment of the inducible dimer. In an aspect, in the inducible CRISPR-Cas system, the inducer energy source is or comprises or consists essentially of or consists of rapamycin. In an aspect, in inducible CRISPR-Cas system, the inducible dimer is an inducible homodimer. In an aspect, in an inducible Cpf1 CRISPR-Cas system, the Cpf1 is AsCpf1, LbCpf1 or FnCpf1.

In an aspect, the invention provides a (non-naturally occurring or engineered) inducible CRISPR-Cas system, comprising: a first CRISPR fusion construct attached to a first half of an inducible heterodimer and a second CRISPR fusion construct attached to a second half of the inducible heterodimer, wherein the first CRISPR fusion construct is operably linked to one or more nuclear localization signals, wherein the second CRISPR fusion construct is operably linked to a nuclear export signal, wherein contact with an inducer energy source brings the first and second halves of the inducible heterodimer together, wherein bringing the first and second halves of the inducible heterodimer together allows the first and second CRISPR fusion constructs to constitute a functional CRISPR (optionally wherein the CRISPR-Cas system comprises a guide RNA (gRNA) comprising a guide sequence capable of hybridizing to a target sequence in a genomic locus of interest in a cell, and wherein the functional CRISPR-Cas system edits the genomic locus to alter gene expression).

Accordingly, the invention comprehends inter alia homodimers as well as heterodimers, dead-CRISPR or CRISPR protein having essentially no nuclease activity, e.g., through mutation, systems or complexes wherein there is one or more NLS and/or one or more NES; functional domain(s) linked to split Cas9; methods, including methods of treatment, and uses.

An inducer energy source may be considered to be simply an inducer or a dimerizing agent. The term ‘inducer energy source’ is used herein throughout for consistency. The inducer energy source (or inducer) acts to reconstitute the enzyme. In some embodiments, the inducer energy source brings the two parts of the enzyme together through the action of the two halves of the inducible dimer. The two halves of the inducible dimer therefore are brought tougher in the presence of the inducer energy source. The two halves of the dimer will not form into the dimer (dimerize) without the inducer energy source.

Thus, the two halves of the inducible dimer cooperate with the inducer energy source to dimerize the dimer. This in turn reconstitutes the CRISPR by bringing the first and second parts of the CRISPR together.

The CRISPR protein fusion constructs each comprise one part of the split CRISPR protein. These are fused, preferably via a linker such as a GlySer linker described herein, to one of the two halves of the dimer. The two halves of the dimer may be substantially the same two monomers that together that form the homodimer, or they may be different monomers that together form the heterodimer. As such, the two monomers can be thought of as one half of the full dimer.

The CRISPR protein is split in the sense that the two parts of the CRISPR protein enzyme substantially comprise a functioning CRISPR protein. That CRISPR protein may function as a genome editing enzyme (when forming a complex with the target DNA and the guide), such as a nickase or a nuclease (cleaving both strands of the DNA), or it may be a dead- CRISPR protein which is essentially a DNA-binding protein with very little or no catalytic activity, due to typically mutation(s) in its catalytic domains.

The two parts of the split CRISPR protein can be thought of as the N′ terminal part and the C′ terminal part of the split CRISPR protein. The fusion is typically at the split point of the CRISPR protein. In other words, the C′ terminal of the N′ terminal part of the split CRISPR protein is fused to one of the dimer halves, whilst the N′ terminal of the C′ terminal part is fused to the other dimer half.

The CRISPR protein does not have to be split in the sense that the break is newly created. The split point is typically designed in silico and cloned into the constructs. Together, the two parts of the split CRISPR protein, the N′ terminal and C′ terminal parts, form a full CRISPR protein, comprising preferably at least 70% or more of the wildtype amino acids (or nucleotides encoding them), preferably at least 80% or more, preferably at least 90% or more, preferably at least 95% or more, and most preferably at least 99% or more of the wildtype amino acids (or nucleotides encoding them). Some trimming may be possible, and mutants are envisaged. Non-functional domains may be removed entirely. What is important is that the two parts may be brought together and that the desired CRISPR protein function is restored or reconstituted.

The dimer may be a homodimer or a heterodimer.

One or more, preferably two, NLSs may be used in operable linkage to the first CRISPR protein construct. One or more, preferably two, NESs may be used in operable linkage to the first Cpf1 construct. The NLSs and/or the NESs preferably flank the split Cpf1-dimer (i.e., half dimer) fusion, i.e., one NLS may be positioned at the N′ terminal of the first CRISPR protein construct and one NLS may be at the C′ terminal of the first CRISPR protein construct. Similarly, one NES may be positioned at the N′ terminal of the second CRISPR construct and one NES may be at the C′ terminal of the second CRISPR construct. Where reference is made to N′ or C′ terminals, it will be appreciated that these correspond to 5′ ad 3′ ends in the corresponding nucleotide sequence.

A preferred arrangement is that the first CRISPR protein construct is arranged 5′-NLS-(N′ terminal CRISPR protein part)-linker-(first half of the dimer)-NLS-3′. A preferred arrangement is that the second CRISPR protein construct is arranged 5′-NES-(second half of the dimer)-linker-(C′ terminal CRISPR protein part)-NES-3′. A suitable promoter is preferably upstream of each of these constructs. The two constructs may be delivered separately or together.

In some embodiments, one or all of the NES(s) in operable linkage to the second CPf1 construct may be swapped out for an NLS. However, this may be typically not preferred and, in other embodiments, the localization signal in operable linkage to the second Cpf1 construct is one or more NES(s).

It will also be appreciated that the NES may be operably linked to the N′ terminal fragment of the split CRISPR protein and that the NLS may be operably linked to the C′ terminal fragment of the split CRISPR protein. However, the arrangement where the NLS is operably linked to the N′ terminal fragment of the split Cpf1 and that the NES is operably linked to the C′ terminal fragment of the split CRISPR protein may be preferred.

The NES functions to localize the second CRISPR protein fusion construct outside of the nucleus, at least until the inducer energy source is provided (e.g., at least until an energy source is provided to the inducer to perform its function). The presence of the inducer stimulates dimerization of the two CRISPR protein fusions within the cytoplasm and makes it thermodynamically worthwhile for the dimerized, first and second, CRISPR protein fusions to localize to the nucleus. Without being bound by theory, Applicants believe that the NES sequesters the second CRISPR protein fusion to the cytoplasm (i.e., outside of the nucleus). The NLS on the first CRISPR protein fusion localizes it to the nucleus. In both cases, Applicants use the NES or NLS to shift an equilibrium (the equilibrium of nuclear transport) to a desired direction. The dimerization typically occurs outside of the nucleus (a very small fraction might happen in the nucleus) and the NLSs on the dimerized complex shift the equilibrium of nuclear transport to nuclear localization, so the dimerized and hence reconstituted CRISPR protein enters the nucleus.

Beneficially, Applicants are able to reconstitute function in the split CRISPR protein. Transient transfection is used to prove the concept and dimerization occurs in the background in the presence of the inducer energy source. No activity is seen with separate fragments of the CRISPR protein. Stable expression through lentiviral delivery is then used to develop this and show that a split CRISPR protein approach can be used.

This present split CRISPR protein approach is beneficial as it allows the CRISPR protein activity to be inducible, thus allowing for temporal control. Furthermore, different localization sequences may be used (i.e., the NES and NLS as preferred) to reduce background activity from auto-assembled complexes. Tissue specific promoters, for example one for each of the first and second CRISPR protein fusion constructs, may also be used for tissue-specific targeting, thus providing spatial control. Two different tissue specific promoters may be used to exert a finer degree of control if required. The same approach may be used in respect of stage-specific promoters or there may a mixture of stage and tissue specific promoters, where one of the first and second Cpf1 fusion constructs is under the control of (i.e. operably linked to or comprises) a tissue-specific promoter, whilst the other of the first and second Cpf1 fusion constructs is under the control of (i.e. operably linked to or comprises) a stage-specific promoter.

The inducible CRISPR protein CRISPR-Cas system comprises one or more nuclear localization sequences (NLSs), as described herein, for example as operably linked to the first CRISPR protein fusion construct. These nuclear localization sequences are ideally of sufficient strength to drive accumulation of said first CRISPR protein fusion construct in a detectable amount in the nucleus of a eukaryotic cell. Without wishing to be bound by theory, it is believed that a nuclear localization sequence is not necessary for CRISPR-Cas complex activity in eukaryotes, but that including such sequences enhances activity of the system, especially as to targeting nucleic acid molecules in the nucleus, and assists with the operation of the present 2-part system.

Equally, the second CRISPR protein fusion construct is operably linked to a nuclear export sequence (NES). Indeed, it may be linked to one or more nuclear export sequences. In other words, the number of export sequences used with the second CRISPR protein fusion construct is preferably 1 or 2 or 3. Typically 2 is preferred, but 1 is enough and so is preferred in some embodiments. Suitable examples of NLS and NES are known in the art. For example, a preferred nuclear export signal (NES) is human protein tyrosin kinase 2. Preferred signals will be species specific.

Where the FRB and FKBP system are used, the FKBP is preferably flanked by nuclear localization sequences (NLSs). Where the FRB and FKBP system are used, the preferred arrangement is N′ terminal CRISPR protein-FRB-NES: C′ terminal Cpf1-FKBP-NLS. Thus, the first CRISPR protein fusion construct would comprise the C′ terminal CRISPR protein part and the second CRISPR protein fusion construct would comprise the N′ terminal CRISPR protein part.

Another beneficial aspect to the present invention is that it may be turned on quickly, i.e. that is has a rapid response. It is believed, without being bound by theory, that CRISPR protein activity can be induced through dimerization of existing (already present) fusion constructs (through contact with the inducer energy source) more rapidly than through the expression (especially translation) of new fusion constructs. As such, the first and second CRISPR protein fusion constructs may be expressed in the target cell ahead of time, i.e. before CRISPR protein activity is required. CRISPR protein activity can then be temporally controlled and then quickly constituted through addition of the inducer energy source, which ideally acts more quickly (to dimerize the heterodimer and thereby provide CRISPR protein activity) than through expression (including induction of transcription) of CRISPR protein delivered by a vector, for example.

Applicants demonstrate that CRISPR protein can be split into two components, which reconstitute a functional nuclease when brought back together. Employing rapamycin sensitive dimerization domains, Applicants generate a chemically inducible CRISPR protein for temporal control of CRISPR protein-mediated genome editing and transcription modulation. Put another way, Applicants demonstrate that CRISPR protein can be rendered chemically inducible by being split into two fragments and that rapamycin-sensitive dimerization domains may be used for controlled reassembly of the CRISPR protein. Applicants show that the re-assembled CRISPR protein may be used to mediate genome editing (through nuclease/nickase activity) as well as transcription modulation (as a DNA-binding domain, the so-called “dead CRISPR protein”).

As such, the use of rapamycin-sensitive dimerization domains is preferred. Reassembly of the CRISPR protein is preferred. Reassembly can be determined by restoration of binding activity. Where the CRISPR protein is a nickase or induces a double-strand break, suitable comparison percentages compared to a wildtype are described herein.

Rapamycin treatments can last 12 days. The dose can be 200 nm. This temporal and/or molar dosage is an example of an appropriate dose for Human embryonic kidney 293FT (HEK293FT) cell lines and this may also be used in other cell lines. This figure can be extrapolated out for therapeutic use in vivo into, for example, mg/kg. However, it is also envisaged that the standard dosage for administering rapamycin to a subject is used here as well. By the “standard dosage”, it is meant the dosage under rapamycin's normal therapeutic use or primary indication (i.e. the dose used when rapamycin is administered for use to prevent organ rejection).

It is noteworthy that the preferred arrangement of CRISPR protein-FRB/FKBP pieces are separate and inactive until rapamycin-induced dimerization of FRB and FKBP results in reassembly of a functional full-length CRISPR protein nuclease. Thus, it is preferred that first CRISPR protein fusion construct attached to a first half of an inducible heterodimer is delivered separately and/or is localized separately from the second Cpf1 fusion construct attached to a first half of an inducible heterodimer.

To sequester the CRISPR protein (N)-FRB fragment in the cytoplasm, where it is less likely to dimerize with the nuclear-localized Cpf1 (C)-FKBP fragment, it is preferable to use on CRISPR protein (N)-FRB a single nuclear export sequence (NES) from the human protein tyrosin kinase 2 (CRISPR protein (N)—FRB-NES). In the presence of rapamycin, CRISPR protein (N)—FRB-NES dimerizes with CRISPR protein (C)-FKBP-2×NLS to reconstitute a complete CRISPR protein, which shifts the balance of nuclear trafficking toward nuclear import and allows DNA targeting.

In some aspects or embodiments, an inducible system for providing a CRISPR protein may be used. In some embodiments, the CRISPR protein is capable, in the presence of an inducer energy source, of forming a CRISPR complex with a target sequence and polynucleotides engineered to complex with the CRISPR protein and the target sequence. In some embodiments, the inducible system comprises: a first fusion protein, or polynucleotides encoding it; and a second fusion protein, or polynucleotides encoding it. In some embodiments, the first fusion protein comprises a first portion of the CRISPR protein, a first half of an inducible dimer and one or more Nuclear Localisation Sequences (NLS); and the second fusion protein comprises a second portion of the CRISPR protein, a second half of the inducible dimer and one or more Nuclear Export Sequences (NES). In some embodiments, contact with the inducer energy source brings the first and second portions of the inducible dimer together, so as to bring the first and second portions of the CRISPR protein together, such that the CRISPR protein is thereby capable of forming the CRISPR complex. In some embodiments, the CRISPR protein or the CRISPR system is inducible. In some embodiments, the CRISPR protein may be provided as a single ‘part.’ In some embodiments, delivery of the CRISPR protein is in protein (including in RNP complex with the polynucleotides) or in nucleotide form (including in mRNA form). In some embodiments, polynucleotides encoding the first fusion protein and polynucleotides encoding second fusion protein are provided on same or different constructs. WO2015/089427 describes an inducible CRISPR-Cas system based on an inducible dimer, which can be a homodimer or heterodimer. The system is also described in Zetsche et al. (Nature Biotechnology 33: 139-142 (2015) DOI: doi:10.1038/nbt.3149). Basically, the CRISPR effector protein is split into two parts, each of which is fused to one half of an inducible dimer, whereby contact with an inducer energy source brings the first and second halves of the inducible dimer together, and bringing the first and second halves of the inducible dimer together allows the first and second CRISPR effector fusion constructs to constitute a functional CRISPR-Cas system, wherein the CRISPR-Cas system comprises a guide RNA (gRNA) comprising a guide sequence capable of hybridizing to a target sequence in a genomic locus of interest in a cell, and wherein the functional CRISPR-Cas system binds to the genomic locus. In particular embodiments, the functional CRISPR-Cas system edits the genomic locus to alter gene expression. In particular embodiments the first half is an FKBP and the second half is an FRB. An inducer energy source may be considered to be simply an inducer or a dimerizing agent as it acts to reconstitute the CRISPR effector protein.

Examples of inducers include light and hormones. A preferred example of first and second light-inducible dimer halves is the CIB1 and CRY2 system. The CIB1 domain is a heterodimeric binding partner of the light-sensitive Cryptochrome 2 (CRY2). In another example, the blue light-responsive Magnet dimerization system (pMag and nMag) may be fused to the two parts of a split Cpf1 protein. In response to light stimulation, pMag and nMag dimerize and Cpf1 reassembles. For example, such system is described in connection with Cas9 in Nihongaki et al. (Nat. Biotechnol. 33, 755-790, 2015). The inducer energy source may be heat, ultrasound, electromagnetic energy or chemical. In a preferred embodiment the inducer energy source may be an antibiotic, a small molecule, a hormone, a hormone derivative, a steroid or a steroid derivative. In a more preferred embodiment, the inducer energy source maybe abscisic acid (ABA), doxycycline (DOX), cumate, rapamycin, 4-hydroxytamoxifen (4OHT), estrogen or ecdysone. The at least one switch may be selected from the group consisting of antibiotic based inducible systems, electromagnetic energy based inducible systems, small molecule based inducible systems, nuclear receptor based inducible systems and hormone based inducible systems. In a more preferred embodiment the at least one switch may be selected from the group consisting of tetracycline (Tet)/DOX inducible systems, light inducible systems, ABA inducible systems, cumate repressor/operator systems, 4OHT/estrogen inducible systems, ecdysone-based inducible systems and FKBP12/FRAP (FKBP12-rapamycin complex) inducible systems. Such inducers are also discussed herein and in PCT/US2013/051418, incorporated herein by reference.

Also, it is described in WO2015/089427 that the half of an inducible dimer can be linked to the effector protein with a linker. Optionally, the CRISPR effector protein has reduced or no nuclease activity, e.g. contains one or more inactivating mutations. Further it is described that one or more functional domains can be associated with one or both parts of the effector protein, WO2015/089427 identifies split points within SpCas9. Similar suitable split points can be identified for Cpf1.

The following table presents non-limiting potential split regions within As and LbCpf1. A split site within such a region may be opportune.

For Fn, As and Lb Cpf1 mutants, it should be readily apparent what the corresponding position for a potential split site is, for example, based on a sequence alignment. For non-Fn, As and Lb enzymes one can use the crystal structure of an ortholog if a relatively high degree of homology exists between the ortholog and the intended Cpf1, or one can use computational prediction.

Further it is described that the first and second fusion constructs of the CRISPR effector protein can be delivered in the same or separate vectors. In particular embodiments, a first half of the inducible dimer is fused to one or more nuclear localization constructs while the second half is fused to one or more nuclear export signals.

The therapeutic methods which involve the use of the inducible dimer comprise the step of administering the vectors comprising the first and second fusion constructs to the subject and administering an inducer energy source to the subject. In particular embodiments, the inducer energy source is rapamycin. It is further envisaged that the methods can involve administering, a repair template, in the same or a different vector as the inducible dimer fragments. An exemplary treatment regimen with Rapamycin can last 12 days.

The use of the split Cpf1 effector protein system described herein allows a further control of the CRISPR-Cas activity. More particularly the use of an inducible system allows for temporal control. In addition, the use of different localization sequences (i.e., the NES and NLS as preferred) can reduce background activity from auto-assembled complexes. Tissue specific promoters, allow for spatial control. Two different tissue specific promoters may be used to exert a finer degree of control if required.

f) Use of Self-Inactivating Systems

Once all copies of a gene in the genome of a cell have been edited, continued CRISPR/Cpf1 expression in that cell is no longer necessary. Indeed, sustained expression is undesirable to avoid off-target effects and other toxicity issues. WO 2015089351 describes self-inactivating CRISPR systems which rely on the use of a non-coding guide target sequence within the CRISPR vector itself Thus, after expression begins, the CRISPR system will lead to its own destruction, but before destruction is complete it will have time to edit the genomic copies of the target gene (which, with a normal point mutation in a diploid cell, requires at most two edits). Accordingly, the methods may involve the use of a self-inactivating CRISPR-Cas system which includes one additional RNA (i.e., guide RNA) that targets the coding sequence for the CRISPR enzyme itself or that targets one or more non-coding guide target sequences complementary to unique sequences present in within the promoter driving expression of the non-coding RNA elements, within the promoter driving expression of the Cpf1 gene, within 100 bp of the ATG translational start codon in the Cpf1 coding sequence, or within the inverted terminal repeat (iTR) of a viral delivery vector, e.g., in the AAV genome.

Similarly, self-inactivating systems which make use of “governing guides” are exemplified in relation to Cas9 in US2015232881A1 (also published as WO2015070083 (A1) referenced elsewhere herein and incorporated herein by reference, and may be extrapolated to Cpf1. More particularly Methods and compositions that use, or include, a nucleic acid, e.g., a DNA, that encodes a Cpf1 molecule or a gRNA molecule, can, in addition, use or include a “governing gRNA molecule.” The governing gRNA molecule can complex with the Cpf1 molecule to inactivate or silence a component of a Cpf1 system. The additional gRNA molecule, referred to herein as a governing gRNA molecule, comprises a targeting domain which targets a component of the Cpf1 system. In an embodiment, the governing gRNA molecule targets and silences (1) a nucleic acid that encodes a Cpf1 molecule (i.e., a Cpf1-targeting gRNA molecule), (2) a nucleic acid that encodes a gRNA molecule (i.e., a gRNA-targeting gRNA molecule), or (3) a nucleic acid sequence engineered into the Cpf1 components that is designed with minimal homology to other nucleic acid sequences in the cell to minimize off-target cleavage (i.e., an engineered control sequence-targeting gRNA molecule).

The targeting sequence for the governing gRNA can be selected to increase regulation or control of the Cpf1 system and/or to reduce or minimize off-target effects of the system. For example, a governing gRNA can minimize undesirable cleavage, e.g., “recleavage” after Cpf1 mediated alteration of a target nucleic acid or off-target cutting of Cpf1, by inactivating (e.g., cleaving) a nucleic acid that encodes a Cpf1 molecule. In an embodiment, a governing gRNA places temporal or other limit(s) on the level of expression or activity of the Cpf1 molecule/gRNA molecule complex. In an embodiment, the governing gRNA reduces off-target or other unwanted activity.

The additional guide RNA can be delivered via a vector, e.g., a separate vector or the same vector that is encoding the CRISPR complex. When provided by a separate vector, the CRISPR RNA that targets Cpf1 expression can be administered sequentially or simultaneously. When administered sequentially, the CRISPR RNA that targets Cpf1 expression is to be delivered after the CRISPR RNA that is intended for e.g. gene editing or gene engineering. This period may be a period of minutes (e.g. 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 60 minutes). This period may be a period of hours (e.g. 2 hours, 4 hours, 6 hours, 8 hours, 12 hours, 24 hours). This period may be a period of days (e.g. 2 days, 3 days, 4 days, 7 days). This period may be a period of weeks (e.g. 2 weeks, 3 weeks, 4 weeks). This period may be a period of months (e.g. 2 months, 4 months, 8 months, 12 months). This period may be a period of years (2 years, 3 years, 4 years). In this fashion, the Cas enzyme associates with a first gRNA capable of hybridizing to a first target, such as a genomic locus or loci of interest and undertakes the function(s) desired of the CRISPR-Cas system (e.g., gene engineering); and subsequently the Cpf1 enzyme may then associate with the second gRNA capable of hybridizing to the sequence comprising at least part of the Cpf1 or CRISPR cassette. Where the gRNA targets the sequences encoding expression of the Cpf1 protein, the enzyme becomes impeded and the system becomes self-inactivating. In the same manner, CRISPR RNA that targets Cpf1 expression applied via, for example liposome, lipofection, nanoparticles, microvesicles as explained herein, may be administered sequentially or simultaneously. Similarly, self-inactivation may be used for inactivation of one or more guide RNA used to target one or more targets.

In some embodiments, a single gRNA is provided that is capable of hybridization to a sequence downstream of a CRISPR enzyme start codon, whereby after a period of time there is a loss of the CRISPR enzyme expression. In some embodiments, one or more gRNA(s) are provided that are capable of hybridization to one or more coding or non-coding regions of the polynucleotide encoding the CRISPR-Cas system, whereby after a period of time there is a inactivation of one or more, or in some cases all, of the CRISPR-Cas systems. In some aspects of the system, and not to be limited by theory, the cell may comprise a plurality of CRISPR-Cas complexes, wherein a first subset of CRISPR complexes comprise a first chiRNA capable of targeting a genomic locus or loci to be edited, and a second subset of CRISPR complexes comprise at least one second chiRNA capable of targeting the polynucleotide encoding the CRISPR-Cas system, wherein the first subset of CRISPR-Cas complexes mediate editing of the targeted genomic locus or loci and the second subset of CRISPR complexes eventually inactivate the CRISPR-Cas system, thereby inactivating further CRISPR-Cas expression in the cell.

Thus the invention provides a CRISPR-Cas system comprising one or more vectors for delivery to a eukaryotic cell, wherein the vector(s) encode(s): (i) a CRISPR enzyme; (ii) a first guide RNA capable of hybridizing to a target sequence in the cell; (iii) a second guide RNA capable of hybridizing to one or more target sequence(s) in the vector which encodes the CRISPR enzyme; (iv) at least one tracr mate sequence; and (v) at least one tracr sequence. The first and second complexes can use the same tracr and tracr mate, thus differing only by the guide sequence, wherein, when expressed within the cell: the first guide RNA directs sequence-specific binding of a first CRISPR complex to the target sequence in the cell; the second guide RNA directs sequence-specific binding of a second CRISPR complex to the target sequence in the vector which encodes the CRISPR enzyme; the CRISPR complexes comprise (a) a tracr mate sequence hybridised to a tracr sequence and (b) a CRISPR enzyme bound to a guide RNA, such that a guide RNA can hybridize to its target sequence; and the second CRISPR complex inactivates the CRISPR-Cas system to prevent continued expression of the CRISPR enzyme by the cell. The CRISPR enzyme can be Cpf1, particularly FnCpf1 or AsCpf1.

Further characteristics of the vector(s), the encoded enzyme, the guide sequences, etc. are disclosed elsewhere herein. For instance, one or both of the guide sequence(s) can be part of a chiRNA sequence which provides the guide, tracr mate and tracr sequences within a single RNA, such that the system can encode (i) a CRISPR enzyme; (ii) a first chiRNA comprising a sequence capable of hybridizing to a first target sequence in the cell, a first tracr mate sequence, and a first tracr sequence; (iii) a second guide RNA capable of hybridizing to the vector which encodes the CRISPR enzyme, a second tracr mate sequence, and a second tracr sequence. Similarly, the enzyme can include one or more NLS, etc.

The various coding sequences (CRISPR enzyme, guide RNAs, tracr and tracr mate) can be included on a single vector or on multiple vectors. For instance, it is possible to encode the enzyme on one vector and the various RNA sequences on another vector, or to encode the enzyme and one chiRNA on one vector, and the remaining chiRNA on another vector, or any other permutation. In general, a system using a total of one or two different vectors is preferred.

Where multiple vectors are used, it is possible to deliver them in unequal numbers, and ideally with an excess of a vector which encodes the first guide RNA relative to the second guide RNA, thereby assisting in delaying final inactivation of the CRISPR system until genome editing has had a chance to occur.

Thus the target sequence in the vector must be capable of inactivating expression of the CRISPR effector protein. Suitable target sequences can be, for instance, near to or within the translational start codon for the Cpf1 coding sequence, in a non-coding sequence in the promoter driving expression of the non-coding RNA elements, within the promoter driving expression of the Cpf1 gene, within 100 bp of the ATG translational start codon in the Cpf1 coding sequence, and/or within the inverted terminal repeat (iTR) of a viral delivery vector, e.g., in the AAV genome. A double stranded break near this region can induce a frame shift in the Cpf1 coding sequence, causing a loss of protein expression. An alternative target sequence for the “self-inactivating” guide RNA would aim to edit/inactivate regulatory regions/sequences needed for the expression of the CRISPR-Cpf1 system or for the stability of the vector. For instance, if the promoter for the Cpf1 coding sequence is disrupted then transcription can be inhibited or prevented. Similarly, if a vector includes sequences for replication, maintenance or stability then it is possible to target these. For instance, in a AAV vector a useful target sequence is within the iTR. Other useful sequences to target can be promoter sequences, polyadenylation sites, etc.

Furthermore, if the guide RNAs are expressed in array format, the “self-inactivating” guide RNAs that target both promoters simultaneously will result in the excision of the intervening nucleotides from within the CRISPR-Cas expression construct, effectively leading to its complete inactivation. Similarly, excision of the intervening nucleotides will result where the guide RNAs target both ITRs, or targets two or more other CRISPR-Cas components simultaneously. Self-inactivation as explained herein is applicable, in general, with CRISPR-Cpf1 systems in order to provide regulation of the CRISPR-Cpf1. For example, self-inactivation as explained herein may be applied to the CRISPR repair of mutations, for example expansion disorders, as explained herein. As a result of this self-inactivation, CRISPR repair is only transiently active.

Addition of non-targeting nucleotides to the 5′ end (e.g. 1-10 nucleotides, preferably 1-5 nucleotides) of the “self-inactivating” guide RNA can be used to delay its processing and/or modify its efficiency as a means of ensuring editing at the targeted genomic locus prior to CRISPR-Cpf1 shutdown.

In one aspect of the self-inactivating AAV-CRISPR-Cpf1 system, plasmids that co-express one or more sgRNA targeting genomic sequences of interest (e.g. 1-2, 1-5, 1-10, 1-15, 1-20, 1-30) may be established with “self-inactivating” sgRNAs that target a Cpf1 sequence at or near the engineered ATG start site (e.g. within 5 nucleotides, within 15 nucleotides, within 30 nucleotides, within 50 nucleotides, within 100 nucleotides). A regulatory sequence in the U6 promoter region can also be targeted with an sgRNA. The U6-driven sgRNAs may be designed in an array format such that multiple sgRNA sequences can be simultaneously released. When first delivered into target tissue/cells (left cell) sgRNAs begin to accumulate while Cpf1 protein levels rise in the nucleus. Cpf1 complexes with all of the sgRNAs to mediate genome editing and self-inactivation of the CRISPR-Cpf1 plasmids.

One aspect of a self-inactivating CRISPR-Cpf1 system is expression of singly or in tandem array format from 1 up to 4 or more different guide sequences; e.g. up to about 20 or about 30 guides sequences. Each individual self-inactivating guide sequence may target a different target. Such may be processed from, e.g. one chimeric pol3 transcript. Pol3 promoters such as U6 or H1 promoters may be used. Pol2 promoters such as those mentioned throughout herein. Inverted terminal repeat (iTR) sequences may flank the Pol3 promoter-sgRNA(s)-Pol2 promoter-Cas9.

In particular embodiments one or more guide(s) edit the one or more target(s) while one or more self-inactivating guides inactivate the CRISPR/Cpf1 system. Thus, for example, the described CRISPR-Cpf1 system for repairing expansion disorders may be directly combined with the self-inactivating CRISPR-Cpf1 system described herein. Such a system may, for example, have two guides directed to the target region for repair as well as at least a third guide directed to self-inactivation of the CRISPR-Cpf1. Reference is made to Application Ser. No. PCT/US2014/069897, entitled “Compositions And Methods Of Use Of Crispr-Cas Systems In Nucleotide Repeat Disorders,” published Dec. 12, 2014 as WO/2015/089351.

In particular embodiments, the gene editing systems described herein are placed under the control of a passcode kill switch, which is a mechanism which efficiently kills the host cell when the conditions of the cell are altered. This is ensured by introducing hybrid LacI-GalR family transcription factors, which require the presence of IPTG to be switched on (Chan et al. 2015 Nature Chemical Biology doi:10.1038/nchembio.1979 which can be used to drive a gene encoding an enzyme critical for cell-survival. By combining different transcription factors sensitive to different chemicals, a “code” can be generated. This system can be used to spatially and temporally control the extent of CRISPR-induced genetic modifications, which can be of interest in different fields including therapeutic applications and may also be of interest to avoid the “escape” of GMOs from their intended environment.

g) Use of “Off-Switches”

In particular embodiments, it may be possible to make use of specific inhibitors and/or agonist of Cpf1. Off-switches and On-switches may be any molecules (i.e. peptides, proteins, small molecules, nucleic acids) capable of interfering with or acting as an agonist for any aspect of the Cas9 effector protein. For instance, Pawluck et al. 2016 (Cell 167, 1-10) describe mobile elements from bacteria that encode protein inhibitors of Cas9. Three families of anti-CRISPRs were found to inhibit N. meningitidis Cas9 in vivo and in vitro. The anti-CRISPRs bind directly to NmeCas9. These proteins are described to be potent “off-switches” for NmeCas9 genome editing in human cells. Methods for identifying small molecules which affect efficiency of Cas9 are described for example by Yu et al. (Cell Stem Cell 16, 142-147, 2015). In certain embodiments small molecules may be used for control Cas9. Maji et al. describe a small molecule-regulated protein degron domain to control Cas9 system editing. Maji et al. “Multidimensional chemical control of CRISPR-Cas9” Nature Chemical Biology (2017) 13:9-12. In certain example embodiments, the inhibitor may be a bacteriophage derived protein. See Rauch et al. “Inhibition of CRISPR-Cas9 with Bacteriophage Proteins” Cell (2017) 168(2):150-158. In certain example embodiments, the anti-CRISPR may inhibit CRISPR-Cas systems by binding to guide molecules. See Shin et al. “Disabling Cas9 by an anti-CRISPR DNA mimic” bioRxiv, Apr. 22, 2017, doi: dx.doi.org/10.1101/129627.

In particular embodiments, intracellular DNA is removed by genetically encoded DNai which responds to a transcriptional input and degrades user-defined DNA as described in Caliando & Voigt, Nature Communications 6: 6989 (2015).

Efficacy—

a. Enzyme Stability

The level of expression of a protein is dependent on many factors, including the quantity of mRNA, its stability and rates of ribosome initiation. The stability or degradation of mRNA is an important factor. Several strategies have been described to increase mRNA stability. One aspect is codon-optimization. It has been found that GC-rich genes are expressed several-fold to over a 100-fold more efficiently than their GC-poor counterparts. This effect could be directly attributed to increased steady-state mRNA levels, and more particularly to efficient transcription or mRNA processing (not decreased degradation) (Kudla et al. Plos Biology dx.doi.org/10.1371/journal.pbio.0040180). Also, it has been found that ribosomal density has a significant effect on the transcript half-life. More particularly, it was found that an increase in stability can be achieved through the incorporation of nucleotide sequences that are capable of forming secondary structures, which often recruit ribosomes, which impede mRNA degrading enzymes. WO2011/141027 describes that slowly-read codons can be positioned in such a way as to cause high ribosome occupancy across a critical region of the 5′ end of the mRNA can increase the half-life of a message by as much as 25%, and produce a similar uplift in protein production. In contrast, positioning even a single slow-read codon before this critical region can significantly destabilize the mRNA and result in an attenuation of protein expression. This understanding enables the design of mRNAs so as to suit the desired functionality. In addition, chemical modifications such as those described for guide sequences herein can be envisaged to increase mRNA stability.

b. Guide Stability

In certain embodiments, the methods make use of chemically modified guide RNAs. Examples of guide RNA chemical modifications include, without limitation, incorporation of 2′-O-methyl (M), 2′-O-methyl 3′phosphorothioate (MS), or 2′-O-methyl 3′thioPACE (MSP) at one or more terminal nucleotides. Such chemically modified guide RNAs can comprise increased stability and increased activity as compared to unmodified guide RNAs, though on-target vs. off-target specificity is not predictable. (See, Hendel, 2015, Nat Biotechnol. 33(9):985-9, doi: 10.1038/nbt.3290, published online 29 Jun. 2015). Chemically modified guide RNAs father include, without limitation, RNAs with phosphorothioate linkages and locked nucleic acid (LNA) nucleotides comprising a methylene bridge between the 2′ and 4′ carbons of the ribose ring.

Select Best Target Site in Gene

a) Selection within a Target Gene

Studies to date suggest that while sgRNA activity can be quite high, there is significant variability among sgRNAs in their ability to generate the desired target cleavage. Efforts have been made to identify design criteria to maximize guide RNA efficacy. Doench et al. (Nat Biotechnol. 2014 December; 32(12): 1262-1267 and Nat Biotechnol. PubMed PMID: 26780180) describe the development of a quantitative model to optimize sgRNA activity prediction, and a tool to use this model for sgRNA design. Accordingly, in particular embodiments, the methods provided herein comprise identifying an optimal guide sequence based on a statistical comparison of active guide RNAs, such as described by Doench et al. (above). In particular embodiments, at least five gRNAs are designed per target and these are tested empirically in cells to generate at least one which has sufficiently high activity.

***Note that there is mention of a manual entitled “]”]How to design CRISPR crRNA for gene disruption “from integrated technologies which apparently mentions concept of “targeting an early 5′ exon of your gene reduces the chances of functional [off-target]” but this link is no longer working.

b) Identification of Suitable Guide Sequence

Currently RNA guides are designed using the reference human genome; however, failing to take into account variation in the human population may confound the therapeutic outcome for a given RNA guide. The recently released ExAC dataset, based on 60,706 individuals, contains on average one variant per eight nucleotides in the human exome (Lek, M. et al. Analysis of protein-coding genetic variation in 60,706 humans. Nature 536, 285-291 (2016)). This highlights the potential for genetic variation to impact the efficacy of certain RNA guides across patient populations for CRISPR-based gene therapy, due to the presence of mismatches between the RNA guide and variants present in the target site of specific patients. To assess this impact, we use the ExAC dataset to catalog variants present in all possible targets in the human reference exome that either (i) disrupt the target PAM sequence or (ii) introduce mismatches between the RNA guide and the genomic DNA, which can collectively be termed target variation ( FIG. 9 a ). For treatment of a patient population, avoiding target variation for RNA guides administered to individual patients will maximize the consistency of outcomes for a genome editing therapeutic. The demonstration of the impact of target variation is illustrated in the examples section herein.

Ideally, personalized genomic medicine would tailor RNA-guided endonuclease therapeutics for each patient. However, it would likely be cost-prohibitive and infeasible from a regulatory standpoint to design an individual RNA guide for each patient receiving a genome editing therapy. The analysis of the impact of genetic variation on the efficacy and safety of RNA-guided endonucleases motivates the following framework to streamline the design and testing of genome editing therapeutics ( FIG. 12 d ). First, use of RNA guides for platinum targets would ensure perfect targeting for 99.99% of patients. Second, these RNA guides need to be further selected to minimize the number of off-target candidates occurring on high frequency haplotypes in the patient population. Third, low frequency variation captured in large scale sequencing datasets can be used to estimate the number of guide RNA-enzyme combinations required to effectively and safely treat different sizes of patient populations. Growth of large scale sequencing datasets will improve the accuracy of these estimates. Fourth, pre-therapeutic whole genome sequencing of individual patients will be needed to select a single approved guide RNA-enzyme combination for treatment. This combination should be a perfect match to the patient's genome and be free of patient-specific off-target candidates. This framework, in combination with rapidly accumulating human sequencing data, which will further refine these selection criteria, will enable the design and validation of genome editing therapeutics minimizing both the number of guide RNA-enzyme combinations necessary for approval and the cost of delivering effective and safe gene therapies to patients.

Accordingly, in particular embodiments, the methods provided herein comprise one or more of the following steps: (1) identifying platinum targets, (2) selection of the guides to minimize the number of off-target candidates occurring on high frequency haplotypes in the patient population; (3) select guide (and/or effector protein) based low frequency variation captured in large scale sequencing datasets to estimate the number of guide RNA-enzyme combinations required to effectively and safely treat different sizes of patient populations, and (4) confirm or select guide based on pre-therapeutic whole genome sequencing of individual patient. In particular embodiments, a “platinum” target is one that does not contain variants occurring at >0.01% allele frequency.

Methods for Determining on/Off-Target Activity and Selecting Suitable Target Sequences/Guides

In certain example embodiments, parameters such as, but not limited to, off-target candidates, PAM restrictiveness, target cleavage efficiency, or effector protein specific may be determined using sequencing-based double-strand break (DSB) detection assays. Example sequencing-based DSB detection assay sChIP-seq (Szilard et al. Nat. Struct. Mol. Biol. 18, 299-305 (2010); Iacovoni et al. EMBO J. 29, 1446-1457 (2010)), BLESS (Crosetto et al. Nat. Methods 10, 361-365 (2013); Ran et al. Nature 520, 186-191 (2015); Slaymaker et al. Science 351, 84-88 (2016)), GUIDEseq (Tsai et al. Nat. Biotech 33, 187-197 (2015)), Digenome-seq (Kim et al. Nat. Methods 12, 237-43 (2015)), IDLV-mediated DNA break capture (Wang et al. Nat. Biotechnol. 33, 179-186 (2015), HTGTS (Frock et al. Nat. Biotechnol. 33, 179-186 (2015)), End-Seq (Canela et al. Mol. Cell 63, 898-911 (2016), and DSBCapture (Lensing et al. Nat. Methods 13, 855-857 (2016). Additional methods that may be used to assess target cleavage efficiency include SITE-Seq (Cameron et al. Nature Methods, 14, 600-606 (2017), and CIRCLE-seq (Tsai et al. Nature Methods 14, 607-614 (2017)).

Methods useful for assessing Cpf1 RNase activity include those disclosed in Zhong et al. Nature Chemical Biology Jun. 19, 2017 doi: 10.1038/NCHEMBIO.2410. Increased RNase activity and the ability to excise multiple CRISPR RNAs (crRNA) from a single RNA polymerase II-driven RNA transcript can simplify modification of multiple genomic targets and can be used to increase the efficiency of Cpf1-mediated editing.

Bliss

Other suitable assays include those described in Yan et al. (“BLISS: quantitative and versatile genome-wide profiling of DNA breaks in situ”, BioRxiv, Dec. 4, 2016, doi: dx.doi.org/10.1101/091629) describe a versatile, sensitive and quantitative method for detecting DSBs applicable to low-input specimens of both cells and tissues that is scalable for high-throughput DSB mapping in multiple samples. Breaks Labeling In Situ and Sequencing (BLISS), features efficient in situ DSB labeling in fixed cells or tissue sections immobilized onto a solid surface, linear amplification of tagged DSBs via T7-mediated in vitro transcription (IVT) for greater sensitivity, and accurate DSB quantification by incorporation of unique molecular identifiers (UMIs).

Curtain

A further method, has been developed which may also be useful in assessing certain parameters disclosed herein. The method allowing on target and off target cutting of a nuclease to be assessed in a direct and unbiased way using in vitro cutting of immobilized nucleic acid molecules. Further reference is made to International Patent Application No. PCT/US2017/028009 entitled “Unbiased Detection of Nucleic Acid Modifications” filed on Jun. 16, 2017.

This method may also be used to select a suitable guide RNA. The method allows the detection of a nucleic acid modification, by performing the following steps: i) contacting one or more nucleic acid molecules immobilized on a solid support (immobilized nucleic acid molecules) with an agent capable of inducing a nucleic acid modification; and ii) sequencing at least part of said one or more immobilized nucleic acid molecules that comprises the nucleic acid modification using a primer specifically binding to a primer binding site. This method further allows the selection of a guide RNA from a plurality of guide RNAs specific for a selected target sequence. In particular embodiments, the method comprises contacting a plurality of nucleic acid molecules immobilized on a solid support (immobilized nucleic acid molecules) with a plurality of RNA-guided nuclease complexes capable of inducing a nucleic acid break, said plurality of RNA-guided nuclease complexes comprising a plurality of different guide RNA's, thereby inducing one or more nucleic acid breaks; attaching an adapter comprising a primer binding site to said one or more immobilized nucleic acid molecules comprising a nucleic acid break; sequencing at least part of said one or more immobilized nucleic acid molecules comprising a nucleic acid break using a primer specifically binding to said primer binding site; and selecting a guide RNA based on location and/or amount of said one or more breaks.

In particular embodiments, the method comprises determining one or more locations in said one or more immobilized nucleic acid molecules comprising a break other than a location comprising said selected target sequence (off-target breaks) and selecting a guide RNA based on said one or more locations. In particular embodiments, step v comprises determining a number of sites in said one or more immobilized nucleic acid molecules comprising off-target breaks and selecting a guide RNA based on said number of sites. In a further embodiment, step iv comprises both determining the location of off-targets breaks and the number of locations of off-target breaks.

Safety

1. Select Protein with Shortest Half-Life

a) Inherent Half-Life of the Effector Protein

The extended presence of an effector protein after having performed its function at the target site is a potential safety concern, both for off-target effects and direct toxicity of the effector protein. It has been reported that upon direct delivery to the cell by LNP, CRISPR effector proteins degrade rapidly within the cell (Kim et al. Genome Res. 2014 June; 24(6): 1012-1019). Where the effector protein is to be expressed from a plasmid, strategies to actively reduce the half-life of the protein may be of interest.

b) Use of Destabilized Domains

In certain embodiments, the methods provided herein involve the use of a Cpf1 effector protein which is associated with or fused to a destabilization domain (DD). The technology relating to the use of destabilizing domains is described in detail in WO2016/106244, which is incorporated by reference herein.

Destabilizing domains (DD) are domains which can confer instability to a wide range of proteins; see, e.g., Miyazaki, J Am Chem Soc. Mar. 7, 2012; 134(9): 3942-3945, and Chung H Nature Chemical Biology Vol. 11 Sep. 2015 pgs 713-720, incorporated herein by reference. DD can be associated with, e.g., fused to, advantageously with a linker, to a CRISPR enzyme, whereby the DD can be stabilized in the presence of a ligand and when there is the absence thereof the DD can become destabilized, whereby the CRISPR enzyme is entirely destabilized, or the DD can be stabilized in the absence of a ligand and when the ligand is present the DD can become destabilized; the DD allows the Cpf1 effector to be regulated or controlled, thereby providing means for regulation or control of the system. For instance, when a protein of interest is expressed as a fusion with the DD tag, it is destabilized and rapidly degraded in the cell, e.g., by proteasomes. Thus, absence of stabilizing ligand leads to a DD-associated Cpf1 being degraded. Peak activity of the Cpf1 effector is relevant to reduce off-target effects and for the general safety of the system. Advantages of the DD system include that it can be dosable, orthogonal (e.g., a ligand only affects its cognate DD so two or more systems can operate independently), transportable (e.g., may work in different cell types or cell lines) and allows for temporal control.

Suitable DD—stabilizing ligand pairs are known in the art and also described in WO2016/106244. The size of Destabilization Domain varies but is typically approx.-approx. 100-300 amino acids in size. Suitable examples include ER50 and/or DHFR50. A corresponding stabilizing ligand for ER50 is, for example, 4HT or CMP8. In some embodiments, one or two DDs may be fused to the N-terminal end of the CRISPR enzyme with one or two DDs fused to the C-terminal of the CRISPR enzyme. While the DD can be provided directly at N and/or C terminal(s) of the Cpf1 effector protein, they can also be fused via a linker, such as a GlySer linker, or an NLS and/or NES. A commercially available DD system is the CloneTech, ProteoTuner™ system; the stabilizing ligand is Shield1. In some embodiments, the stabilizing ligand is a ‘small molecule’, preferably it is cell-permeable and has a high affinity for its corresponding DD.

2. Select Least Immunogenic RNP

When administering an agent to a mammal, there is always the risk of an immune response to the agent and/or its delivery vehicle. Circumventing the immune response is a major challenge for most delivery vehicles. Viral vectors, which express immunogenic epitopes within the organism typically induce an immune response. Nanoparticle and lipid-based vectors to some extent address this problem. Yin et al. demonstrate a therapeutic approach combining viral delivery of the guide RNA with lipid nanoparticle-mediated delivery of the CRISPR effector protein (Nature Biotechnology 34:328-33(2016)). Ziris et al. describes cationic-lipid mediated delivery of Cas9:guideRNA nuclease complexes to cells. The CRISPR effector proteins, which are of bacterial origin, also inherently carry the risk of eliciting an immune response. This may be addressed by humanizing the Cpf1 effector protein.

3. Introduce Modifications in Guide RNA to Minimize Immunogenicity

Chemical modifications of RNAs have been used to avoid reactions of the innate immune system. Judge et al. (2006) demonstrated that immune stimulation by synthetic siRNA can be completely abrogated by selective incorporation of 2′-O-methyl (2′OMe) uridine or guanosine nucleosides into one strand of the siRNA duplex (Mol. Ther., 13 (2006), pp. 494-505). Cekaite et al. (J. Mol. Biol., 365 (2007), pp. 90-108) observed that replacement of only uridine bases of siRNA with either 2′-fluoro or 2′-O-methyl modified counterparts abrogated upregulation of genes involved in the regulation of the immune response. Similarly Hendel et al. tested sgRNAs with both backbone and sugar modifications that confer nuclease stability and can reduce immunostimulatory effects (Hendel et al., Nat. Biotechnol., 33 (2015), pp. 985-989).

Accordingly, in particular embodiments, the methods comprise modifying the guide RNA so as to minimize immunogenicity using one or more of these methods.

Identify Optimal Dosage to Minimize Toxicity and Maximize Specificity

It is generally accepted that the dosage of CRISPR components will be relevant to toxicity and specificity of the system (Pattanayak et al. Nat Biotechnol. 2013 September; 31(9): 839-843). Hsu et al. (Nat Biotechnol. 2013 September; 31(9): 827-832) demonstrated that the dosage of SpCas9 and sgRNA can be titrated to address these issues. In certain example embodiments, toxicity is minimized by saturating complex with guide by either pre-forming complex, putting guide under control of a strong promoter, or via timing of delivery to ensure saturating conditions available during expression of the effector protein.

Identifying Appropriate Delivery Vector

In some embodiments, the components of the CRISPR system may be delivered in various form, such as combinations of DNA/RNA or RNA/RNA or protein/RNA. For example, the Cpf1 may be delivered as a DNA-coding polynucleotide or an RNA-coding polynucleotide or as a protein. The guide may be delivered as a DNA-coding polynucleotide or an RNA. All possible combinations are envisioned, including mixed forms of delivery.

In some aspects, the invention provides methods comprising delivering one or more polynucleotides, such as or one or more vectors as described herein, one or more transcripts thereof, and/or one or proteins transcribed therefrom, to a host cell.

Vectors

Conventional viral and non-viral based gene transfer methods can be used to introduce nucleic acids in mammalian cells or target tissues. Such methods can be used to administer nucleic acids encoding components of a nucleic acid-targeting system to cells in culture, or in a host organism. Non-viral vector delivery systems include DNA plasmids, RNA (e.g. a transcript of a vector described herein), naked nucleic acid, and nucleic acid complexed with a delivery vehicle, such as a liposome. Viral vector delivery systems include DNA and RNA viruses, which have either episomal or integrated genomes after delivery to the cell. For a review of gene therapy procedures, see Anderson, Science 256:808-813 (1992); Nabel & Felgner, TIBTECH 11:211-217 (1993); Mitani & Caskey, TIBTECH 11:162-166 (1993); Dillon, TIBTECH 11:167-175 (1993); Miller, Nature 357:455-460 (1992); Van Brunt, Biotechnology 6(10):1149-1154 (1988); Vigne, Restorative Neurology and Neuroscience 8:35-36 (1995); Kremer & Perricaudet, British Medical Bulletin 51(1):31-44 (1995); Haddada et al., in Current Topics in Microbiology and Immunology, Doerfler and Bohm (eds) (1995); and Yu et al., Gene Therapy 1:13-26 (1994).

Methods of non-viral delivery of nucleic acids include lipofection, nucleofection, microinjection, biolistics, virosomes, liposomes, immunoliposomes, polycation or lipid:nucleic acid conjugates, naked DNA, artificial virions, and agent-enhanced uptake of DNA. Lipofection is described in e.g., U.S. Pat. Nos. 5,049,386, 4,946,787; and 4,897,355) and lipofection reagents are sold commercially (e.g., Transfectam™ and Lipofectin™). Cationic and neutral lipids that are suitable for efficient receptor-recognition lipofection of polynucleotides include those of Felgner, WO 91/17424; WO 91/16024. Delivery can be to cells (e.g. in vitro or ex vivo administration) or target tissues (e.g. in vivo administration).

Plasmid delivery involves the cloning of a guide RNA into a CRISPR effector protein expressing plasmid and transfecting the DNA in cell culture. Plasmid backbones are available commercially and no specific equipment is required. They have the advantage of being modular, capable of carrying different sizes of CRISPR effector coding sequences (including those encoding larger sized proteins) as well as selection markers. Both an advantage of plasmids is that they can ensure transient, but sustained expression. However, delivery of plasmids is not straightforward such that in vivo efficiency is often low. The sustained expression can also be disadvantageous in that it can increase off-target editing. In addition excess build-up of the CRISPR effector protein can be toxic to the cells. Finally, plasmids always hold the risk of random integration of the dsDNA in the host genome, more particularly in view of the double-stranded breaks being generated (on and off-target).

The preparation of lipid:nucleic acid complexes, including targeted liposomes such as immunolipid complexes, is well known to one of skill in the art (see, e.g., Crystal, Science 270:404-410 (1995); Blaese et al., Cancer Gene Ther. 2:291-297 (1995); Behr et al., Bioconjugate Chem. 5:382-389 (1994); Remy et al., Bioconjugate Chem. 5:647-654 (1994); Gao et al., Gene Therapy 2:710-722 (1995); Ahmad et al., Cancer Res. 52:4817-4820 (1992); U.S. Pat. Nos. 4,186,183, 4,217,344, 4,235,871, 4,261,975, 4,485,054, 4,501,728, 4,774,085, 4,837,028, and 4,946,787). This is discussed more in detail below.

The advantages and disadvantages of Plasmid delivery are described by Plasmid delivery involves the cloning of a guide RNA into a CRISPR effector protein expressing plasmid and transfecting the DNA in cell culture. Plasmid backbones are available commercially and no specific equipment is required. They have the advantage of being modular, capable of carrying different sizes of CRISPR effector coding sequences (including those encoding larger sized proteins) as well as selection markers. Both an advantage of plasmids is that they can ensure transient, but sustained expression. However, delivery of plasmids is not straightforward such that in vivo efficiency is often low. The sustained expression can also be disadvantageous in that it can increase off-target editing. In addition excess build-up of the CRISPR effector protein can be toxic to the cells. Finally, plasmids always hold the risk of random integration of the dsDNA in the host genome, more particularly in view of the double-stranded breaks being generated (on and off-target). The preparation of lipid:nucleic acid complexes, including targeted liposomes such as immunolipid complexes, is well known to one of skill in the art (see, e.g., Crystal, Science 270:404-410 (1995); Blaese et al., Cancer Gene Ther. 2:291-297 (1995); Behr et al., Bioconjugate Chem. 5:382-389 (1994); Remy et al., Bioconjugate Chem. 5:647-654 (1994); Gao et al., Gene Therapy 2:710-722 (1995); Ahmad et al., Cancer Res. 52:4817-4820 (1992); U.S. Pat. Nos. 4,186,183, 4,217,344, 4,235,871, 4,261,975, 4,485,054, 4,501,728, 4,774,085, 4,837,028, and 4,946,787). This is discussed more in detail below.

The use of RNA or DNA viral based systems for the delivery of nucleic acids takes advantage of highly evolved processes for targeting a virus to specific cells in the body and trafficking the viral payload to the nucleus. Viral vectors can be administered directly to patients (in vivo) or they can be used to treat cells in vitro, and the modified cells may optionally be administered to patients (ex vivo). Conventional viral based systems could include retroviral, lentivirus, adenoviral, adeno-associated and herpes simplex virus vectors for gene transfer. Integration in the host genome is possible with the retrovirus, lentivirus, and adeno-associated virus gene transfer methods, often resulting in long term expression of the inserted transgene. Additionally, high transduction efficiencies have been observed in many different cell types and target tissues.

The tropism of a retrovirus can be altered by incorporating foreign envelope proteins, expanding the potential target population of target cells. Lentiviral vectors are retroviral vectors that are able to transduce or infect non-dividing cells and typically produce high viral titers. Selection of a retroviral gene transfer system would therefore depend on the target tissue. Retroviral vectors are comprised of cis-acting long terminal repeats with packaging capacity for up to 6-10 kb of foreign sequence. The minimum cis-acting LTRs are sufficient for replication and packaging of the vectors, which are then used to integrate the therapeutic gene into the target cell to provide permanent transgene expression. Widely used retroviral vectors include those based upon murine leukemia virus (MuLV), gibbon ape leukemia virus (GaLV), Simian Immuno deficiency virus (SIV), human immuno deficiency virus (HIV), and combinations thereof (see, e.g., Buchscher et al., J. Virol. 66:2731-2739 (1992); Johann et al., J. Virol. 66:1635-1640 (1992); Sommnerfelt et al., Virol. 176:58-59 (1990); Wilson et al., J. Virol. 63:2374-2378 (1989); Miller et al., J. Virol. 65:2220-2224 (1991); PCT/US94/05700).

In applications where transient expression is preferred, adenoviral based systems may be used. Adenoviral based vectors are capable of very high transduction efficiency in many cell types and do not require cell division. With such vectors, high titer and levels of expression have been obtained. This vector can be produced in large quantities in a relatively simple system. Adeno-associated virus (“AAV”) vectors may also be used to transduce cells with target nucleic acids, e.g., in the in vitro production of nucleic acids and peptides, and for in vivo and ex vivo gene therapy procedures (see, e.g., West et al., Virology 160:38-47 (1987); U.S. Pat. No. 4,797,368; WO 93/24641; Kotin, Human Gene Therapy 5:793-801 (1994); Muzyczka, J. Clin. Invest. 94:1351 (1994). Construction of recombinant AAV vectors are described in a number of publications, including U.S. Pat. No. 5,173,414; Tratschin et al., Mol. Cell. Biol. 5:3251-3260 (1985); Tratschin, et al., Mol. Cell. Biol. 4:2072-2081 (1984); Hermonat & Muzyczka, PNAS 81:6466-6470 (1984); and Samulski et al., J. Virol. 63:03822-3828 (1989).

The invention provides AAV that contains or consists essentially of an exogenous nucleic acid molecule encoding a CRISPR system, e.g., a plurality of cassettes comprising or consisting a first cassette comprising or consisting essentially of a promoter, a nucleic acid molecule encoding a CRISPR-associated (Cas) protein (putative nuclease or helicase proteins), e.g., Cpf1 and a terminator, and a two, or more, advantageously up to the packaging size limit of the vector, e.g., in total (including the first cassette) five, cassettes comprising or consisting essentially of a promoter, nucleic acid molecule encoding guide RNA (gRNA) and a terminator (e.g., each cassette schematically represented as Promoter-gRNA1-terminator, Promoter-gRNA2-terminator Promoter-gRNA(N)-terminator (where N is a number that can be inserted that is at an upper limit of the packaging size limit of the vector), or two or more individual rAAVs, each containing one or more than one cassette of a CRISPR system, e.g., a first rAAV containing the first cassette comprising or consisting essentially of a promoter, a nucleic acid molecule encoding Cas, e.g., Cas (Cpf1) and a terminator, and a second rAAV containing a plurality, four, cassettes comprising or consisting essentially of a promoter, nucleic acid molecule encoding guide RNA (gRNA) and a terminator (e.g., each cassette schematically represented as Promoter-gRNA1-terminator, Promoter-gRNA2-terminator Promoter-gRNA(N)-terminator (where N is a number that can be inserted that is at an upper limit of the packaging size limit of the vector). As rAAV is a DNA virus, the nucleic acid molecules in the herein discussion concerning AAV or rAAV are advantageously DNA. The promoter is in some embodiments advantageously human Synapsin I promoter (hSyn). Additional methods for the delivery of nucleic acids to cells are known to those skilled in the art. See, for example, US20030087817, incorporated herein by reference.

In another embodiment, Cocal vesiculovirus envelope pseudotyped retroviral vector particles are contemplated (see, e.g., US Patent Publication No. 20120164118 assigned to the Fred Hutchinson Cancer Research Center). Cocal virus is in the Vesiculovirus genus, and is a causative agent of vesicular stomatitis in mammals. Cocal virus was originally isolated from mites in Trinidad (Jonkers et al., Am. J. Vet. Res. 25:236-242 (1964)), and infections have been identified in Trinidad, Brazil, and Argentina from insects, cattle, and horses. Many of the vesiculoviruses that infect mammals have been isolated from naturally infected arthropods, suggesting that they are vector-borne. Antibodies to vesiculoviruses are common among people living in rural areas where the viruses are endemic and laboratory-acquired; infections in humans usually result in influenza-like symptoms. The Cocal virus envelope glycoprotein shares 71.5% identity at the amino acid level with VSV-G Indiana, and phylogenetic comparison of the envelope gene of vesiculoviruses shows that Cocal virus is serologically distinct from, but most closely related to, VSV-G Indiana strains among the vesiculoviruses. Jonkers et al., Am. J. Vet. Res. 25:236-242 (1964) and Travassos da Rosa et al., Am. J. Tropical Med. & Hygiene 33:999-1006 (1984). The Cocal vesiculovirus envelope pseudotyped retroviral vector particles may include for example, lentiviral, alpharetroviral, betaretroviral, gammaretroviral, deltaretroviral, and epsilonretroviral vector particles that may comprise retroviral Gag, Pol, and/or one or more accessory protein(s) and a Cocal vesiculovirus envelope protein. Within certain aspects of these embodiments, the Gag, Pol, and accessory proteins are lentiviral and/or gammaretroviral.

In some embodiments, a host cell is transiently or non-transiently transfected with one or more vectors described herein. In some embodiments, a cell is transfected as it naturally occurs in a subject optionally to be reintroduced therein. In some embodiments, a cell that is transfected is taken from a subject. In some embodiments, the cell is derived from cells taken from a subject, such as a cell line. A wide variety of cell lines for tissue culture are known in the art. Examples of cell lines include, but are not limited to, C8161, CCRF-CEM, MOLT, mIMCD-3, NHDF, HeLa-S3, Huh1, Huh4, Huh7, HUVEC, HASMC, HEKn, HEKa, MiaPaCell, Panc1, PC-3, TF1, CTLL-2, C1R, Rath, CV1, RPTE, A10, T24, J82, A375, ARH-77, Calu1, SW480, SW620, SKOV3, SK-UT, CaCo2, P388D1, SEM-K2, WEHI-231, HB56, TIB55, Jurkat, J45.01, LRMB, Bcl-1, BC-3, IC21, DLD2, Raw264.7, NRK, NRK-52E, MRCS, MEF, Hep G2, HeLa B, HeLa T4, COS, COS-1, COS-6, COS-M6A, BS-C-1 monkey kidney epithelial, BALB/3T3 mouse embryo fibroblast, 3T3 Swiss, 3T3-L1, 132-d5 human fetal fibroblasts; 10.1 mouse fibroblasts, 293-T, 3T3, 721, 9L, A2780, A2780ADR, A2780cis, A172, A20, A253, A431, A-549, ALC, B16, B35, BCP-1 cells, BEAS-2B, bEnd.3, BHK-21, BR 293, BxPC3, C3H-10T1/2, C6/36, Cal-27, CHO, CHO-7, CHO-IR, CHO-K1, CHO-K2, CHO-T, CHO Dhfr −/−, COR-L23, COR-L23/CPR, COR-L2315010, COR-L23/R23, COS-7, COV-434, CML T1, CMT, CT26, D17, DH82, DU145, DuCaP, EL4, EM2, EM3, EMT6/AR1, EMT6/AR10.0, FM3, H1299, H69, HB54, HB55, HCA2, HEK-293, HeLa, Hepalc1c7, HL-60, HMEC, HT-29, Jurkat, JY cells, K562 cells, Ku812, KCL22, KG1, KYO1, LNCap, Ma-Mel 1-48, MC-38, MCF-7, MCF-10A, MDA-MB-231, MDA-MB-468, MDA-MB-435, MDCK II, MDCK II, MOR/0.2R, MONO-MAC 6, MTD-1A, MyEnd, NCI-H69/CPR, NCI-H69/LX10, NCI-H69/LX20, NCI-H69/LX4, NIH-3T3, NALM-1, NW-145, OPCN/OPCT cell lines, Peer, PNT-1A /PNT 2, RenCa, RIN-5F, RMA/RMAS, Saos-2 cells, Sf-9, SkBr3, T2, T-47D, T84, THP1 cell line, U373, U87, U937, VCaP, Vero cells, WM39, WT-49, X63, YAC-1, YAR, and transgenic varieties thereof. Cell lines are available from a variety of sources known to those with skill in the art (see, e.g., the American Type Culture Collection (ATCC) (Manassas, Va.)). In some embodiments, a cell transfected with one or more vectors described herein is used to establish a new cell line comprising one or more vector-derived sequences. In some embodiments, a cell transiently transfected with the components of a CRISPR system as described herein (such as by transient transfection of one or more vectors, or transfection with RNA), and modified through the activity of a CRISPR complex, is used to establish a new cell line comprising cells containing the modification but lacking any other exogenous sequence. In some embodiments, cells transiently or non-transiently transfected with one or more vectors described herein, or cell lines derived from such cells are used in assessing one or more test compounds.

In some embodiments it is envisaged to introduce the RNA and/or protein directly to the host cell. For instance, the CRISPR effector can be delivered as CRISPR effector-encoding mRNA together with an in vitro transcribed guide RNA. Such methods can reduce the time to ensure effect of the CRISPR effector protein and further prevents long-term expression of the CRISPR system components.

In some embodiments the RNA molecules of the invention are delivered in liposome or lipofectin formulations and the like and can be prepared by methods well known to those skilled in the art. Such methods are described, for example, in U.S. Pat. Nos. 5,593,972, 5,589,466, and 5,580,859, which are herein incorporated by reference. Delivery systems aimed specifically at the enhanced and improved delivery of siRNA into mammalian cells have been developed, (see, for example, Shen et al FEBS Let. 2003, 539:111-114; Xia et al., Nat. Biotech. 2002, 20:1006-1010; Reich et al., Mol. Vision. 2003, 9: 210-216; Sorensen et al., J. Mol. Biol. 2003, 327: 761-766; Lewis et al., Nat. Gen. 2002, 32: 107-108 and Simeoni et al., NAR 2003, 31, 11: 2717-2724) and may be applied to the present invention. siRNA has recently been successfully used for inhibition of gene expression in primates (see for example. Tolentino et al., Retina 24(4):660 which may also be applied to the present invention.

Indeed, RNA delivery is a useful method of in vivo delivery. It is possible to deliver Cpf1 and gRNA (and, for instance, HR repair template) into cells using liposomes or nanoparticles. Thus delivery of the CRISPR enzyme, such as a Cpf1 and/or delivery of the RNAs of the invention may be in RNA form and via microvesicles, liposomes or particle or particles. For example, Cpf1 mRNA and gRNA can be packaged into liposomal particles for delivery in vivo. Liposomal transfection reagents such as lipofectamine from Life Technologies and other reagents on the market can effectively deliver RNA molecules into the liver.

Means of delivery of RNA also preferred include delivery of RNA via particles (Cho, S., Goldberg, M., Son, S., Xu, Q., Yang, F., Mei, Y., Bogatyrev, S., Langer, R. and Anderson, D., Lipid-like nanoparticles for small interfering RNA delivery to endothelial cells, Advanced Functional Materials, 19: 3112-3118, 2010) or exosomes (Schroeder, A., Levins, C., Cortez, C., Langer, R., and Anderson, D., Lipid-based nanotherapeutics for siRNA delivery, Journal of Internal Medicine, 267: 9-21, 2010, PMID: 20059641). Indeed, exosomes have been shown to be particularly useful in delivery siRNA, a system with some parallels to the CRISPR system. For instance, El-Andaloussi S, et al. (“Exosome-mediated delivery of siRNA in vitro and in vivo.” Nat Protoc. 2012 December; 7(12):2112-26. doi: 10.1038/nprot.2012.131. Epub 2012 Nov. 15.) describe how exosomes are promising tools for drug delivery across different biological barriers and can be harnessed for delivery of siRNA in vitro and in vivo. Their approach is to generate targeted exosomes through transfection of an expression vector, comprising an exosomal protein fused with a peptide ligand. The exosomes are then purify and characterized from transfected cell supernatant, then RNA is loaded into the exosomes. Delivery or administration according to the invention can be performed with exosomes, in particular but not limited to the brain. Vitamin E (α-tocopherol) may be conjugated with CRISPR-Cas and delivered to the brain along with high density lipoprotein (HDL), for example in a similar manner as was done by Uno et al. (HUMAN GENE THERAPY 22:711-719 (June 2011)) for delivering short-interfering RNA (siRNA) to the brain. Mice were infused via Osmotic minipumps (model 1007D; Alzet, Cupertino, Calif.) filled with phosphate-buffered saline (PBS) or free TocsiBACE or Toc-siBACE/HDL and connected with Brain Infusion Kit 3 (Alzet). A brain-infusion cannula was placed about 0.5 mM posterior to the bregma at midline for infusion into the dorsal third ventricle. Uno et al. found that as little as 3 nmol of Toc-siRNA with HDL could induce a target reduction in comparable degree by the same ICV infusion method. A similar dosage of CRISPR-Cas conjugated to α-tocopherol and co-administered with HDL targeted to the brain may be contemplated for humans in the present invention, for example, about 3 nmol to about 3 μmol of CRISPR-Cas targeted to the brain may be contemplated. Zou et al. ((HUMAN GENE THERAPY 22:465-475 (April 2011)) describes a method of lentiviral-mediated delivery of short-hairpin RNAs targeting PKCγ for in vivo gene silencing in the spinal cord of rats. Zou et al. administered about 10 μl of a recombinant lentivirus having a titer of 1×10 9 transducing units (TU)/ml by an intrathecal catheter. A similar dosage of CRISPR-Cas expressed in a lentiviral vector targeted to the brain may be contemplated for humans in the present invention, for example, about 10-50 ml of CRISPR-Cas targeted to the brain in a lentivirus having a titer of 1×10 9 transducing units (TU)/ml may be contemplated.

Vector delivery, e.g., plasmid, viral delivery: The CRISPR enzyme, for instance a Cpf1, and/or any of the present RNAs, for instance a guide RNA, can be delivered using any suitable vector, e.g., plasmid or viral vectors, such as adeno associated virus (AAV), lentivirus, adenovirus or other viral vector types, or combinations thereof. Cpf1 and one or more guide RNAs can be packaged into one or more vectors, e.g., plasmid or viral vectors. In some embodiments, the vector, e.g., plasmid or viral vector is delivered to the tissue of interest by, for example, an intramuscular injection, while other times the delivery is via intravenous, transdermal, intranasal, oral, mucosal, or other delivery methods. Such delivery may be either via a single dose, or multiple doses. One skilled in the art understands that the actual dosage to be delivered herein may vary greatly depending upon a variety of factors, such as the vector choice, the target cell, organism, or tissue, the general condition of the subject to be treated, the degree of transformation/modification sought, the administration route, the administration mode, the type of transformation/modification sought, etc.

Such a dosage may further contain, for example, a carrier (water, saline, ethanol, glycerol, lactose, sucrose, calcium phosphate, gelatin, dextran, agar, pectin, peanut oil, sesame oil, etc.), a diluent, a pharmaceutically-acceptable carrier (e.g., phosphate-buffered saline), a pharmaceutically-acceptable excipient, and/or other compounds known in the art. The dosage may further contain one or more pharmaceutically acceptable salts such as, for example, a mineral acid salt such as a hydrochloride, a hydrobromide, a phosphate, a sulfate, etc.; and the salts of organic acids such as acetates, propionates, malonates, benzoates, etc. Additionally, auxiliary substances, such as wetting or emulsifying agents, pH buffering substances, gels or gelling materials, flavorings, colorants, microspheres, polymers, suspension agents, etc. may also be present herein. In addition, one or more other conventional pharmaceutical ingredients, such as preservatives, humectants, suspending agents, surfactants, antioxidants, anticaking agents, fillers, chelating agents, coating agents, chemical stabilizers, etc. may also be present, especially if the dosage form is a reconstitutable form. Suitable exemplary ingredients include microcrystalline cellulose, carboxymethylcellulose sodium, polysorbate 80, phenylethyl alcohol, chlorobutanol, potassium sorbate, sorbic acid, sulfur dioxide, propyl gallate, the parabens, ethyl vanillin, glycerin, phenol, parachlorophenol, gelatin, albumin and a combination thereof A thorough discussion of pharmaceutically acceptable excipients is available in REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Pub. Co., N.J. 1991) which is incorporated by reference herein.

In an embodiment herein the delivery is via an adenovirus, which may be at a single booster dose containing at least 1×105 particles (also referred to as particle units, pu) of adenoviral vector. In an embodiment herein, the dose preferably is at least about 1×106 particles (for example, about 1×106-1 x 1012 particles), more preferably at least about 1×107 particles, more preferably at least about 1×108 particles (e.g., about 1×108-1×1011 particles or about 1×108-1×1012 particles), and most preferably at least about 1×100 particles (e.g., about 1×109-1×1010 particles or about 1×109-1×1012 particles), or even at least about 1×1010 particles (e.g., about 1×1010-1×1012 particles) of the adenoviral vector. Alternatively, the dose comprises no more than about 1×1014 particles, preferably no more than about 1×1013 particles, even more preferably no more than about 1×1012 particles, even more preferably no more than about 1×1011 particles, and most preferably no more than about 1×1010 particles (e.g., no more than about 1×109 articles). Thus, the dose may contain a single dose of adenoviral vector with, for example, about 1×106 particle units (pu), about 2×106 pu, about 4×106 pu, about 1×107 pu, about 2×107 pu, about 4×107 pu, about 1×108 pu, about 2×108 pu, about 4×108 pu, about 1×109 pu, about 2×109 pu, about 4×109 pu, about 1×1010 pu, about 2×1010 pu, about 4 x 1010 pu, about 1×1011 pu, about 2×1011 pu, about 4×1011 pu, about 1×1012 pu, about 2×1012 pu, or about 4×1012 pu of adenoviral vector. See, for example, the adenoviral vectors in U.S. Pat. No. 8,454,972 B2 to Nabel, et. al., granted on Jun. 4, 2013; incorporated by reference herein, and the dosages at col 29, lines 36-58 thereof. In an embodiment herein, the adenovirus is delivered via multiple doses.

In an embodiment herein, the delivery is via an AAV. A therapeutically effective dosage for in vivo delivery of the AAV to a human is believed to be in the range of from about 20 to about 50 ml of saline solution containing from about 1×1010 to about 1×1010 functional AAV/ml solution. The dosage may be adjusted to balance the therapeutic benefit against any side effects. In an embodiment herein, the AAV dose is generally in the range of concentrations of from about 1×105 to 1×1050 genomes AAV, from about 1×108 to 1×1020 genomes AAV, from about 1×1010 to about 1×1016 genomes, or about 1×1011 to about 1×1016 genomes AAV. A human dosage may be about 1×1013 genomes AAV. Such concentrations may be delivered in from about 0.001 ml to about 100 ml, about 0.05 to about 50 ml, or about 10 to about 25 ml of a carrier solution. Other effective dosages can be readily established by one of ordinary skill in the art through routine trials establishing dose response curves. See, for example, U.S. Pat. No. 8,404,658 B2 to Hajjar, et al., granted on Mar. 26, 2013, at col. 27, lines 45-60.

Among vectors that may be used in the practice of the invention, integration in the host genome of a cell is possible with retrovirus gene transfer methods, often resulting in long term expression of the inserted transgene. In a preferred embodiment the retrovirus is a lentivirus. Additionally, high transduction efficiencies have been observed in many different cell types and target tissues. The tropism of a retrovirus can be altered by incorporating foreign envelope proteins, expanding the potential target population of target cells. A retrovirus can also be engineered to allow for conditional expression of the inserted transgene, such that only certain cell types are infected by the lentivirus. Cell type specific promoters can be used to target expression in specific cell types. Lentiviral vectors are retroviral vectors (and hence both lentiviral and retroviral vectors may be used in the practice of the invention). Moreover, lentiviral vectors are preferred as they are able to transduce or infect non-dividing cells and typically produce high viral titers. Selection of a retroviral gene transfer system may therefore depend on the target tissue. Retroviral vectors are comprised of cis-acting long terminal repeats with packaging capacity for up to 6-10 kb of foreign sequence. The minimum cis-acting LTRs are sufficient for replication and packaging of the vectors, which are then used to integrate the desired nucleic acid into the target cell to provide permanent expression. Widely used retroviral vectors that may be used in the practice of the invention include those based upon murine leukemia virus (MuLV), gibbon ape leukemia virus (GaLV), Simian Immuno deficiency virus (SIV), human immuno deficiency virus (HIV), and combinations thereof (see, e.g., Buchscher et al., (1992) J. Virol. 66:2731-2739; Johann et al., (1992) J. Virol. 66:1635-1640; Sommnerfelt et al., (1990) Virol. 176:58-59; Wilson et al., (1998) J. Virol. 63:2374-2378; Miller et al., (1991) J. Virol. 65:2220-2224; PCT/US94/05700). Zou et al. administered about 10 μl of a recombinant lentivirus having a titer of 1×109 transducing units (TU)/ml by an intrathecal catheter. These sort of dosages can be adapted or extrapolated to use of a retroviral or lentiviral vector in the present invention.

Vector Packaging of Cpf1

Ways to package inventive Cpf1 coding nucleic acid molecules, e.g., DNA, into vectors, e.g., viral vectors, to mediate genome modification in vivo include:

To achieve NHEJ-mediated gene knockout: Single virus vector: Vector containing two or more expression cassettes: Promoter-Cpf1 coding nucleic acid molecule-terminator Promoter-gRNA 1-terminator Promoter-gRNA2-terminator Promoter-gRNA(N)-terminator (up to size limit of vector) Double virus vector: Vector 1 containing one expression cassette for driving the expression of Cpf1 Promoter-Cpf1 coding nucleic acid molecule-terminator Vector 2 containing one more expression cassettes for driving the expression of one or more guideRNAs Promoter-gRNA1-terminator Promoter-gRNA(N)-terminator (up to size limit of vector) To mediate homology-directed repair. In addition to the single and double virus vector approaches described above, an additional vector can be used to deliver a homology-direct repair template.

The promoter used to drive Cpf1 coding nucleic acid molecule expression can include:

AAV ITR can serve as a promoter: this is advantageous for eliminating the need for an additional promoter element (which can take up space in the vector). The additional space freed up can be used to drive the expression of additional elements (gRNA, etc.). Also, ITR activity is relatively weaker, so can be used to reduce potential toxicity due to over expression of Cpf1. For ubiquitous expression, promoters that can be used include: CMV, CAG, CBh, PGK, SV40, Ferritin heavy or light chains, etc.

For brain or other CNS expression, can use promoters: Synapsin I for all neurons, CaMKIIalpha for excitatory neurons, GAD67 or GAD65 or VGAT for GABAergic neurons, etc.

For liver expression, can use Albumin promoter.

For lung expression, can use SP-B.

For endothelial cells, can use ICAM.

For hematopoietic cells can use IFNbeta or CD45.

For Osteoblasts can one can use the OG-2.

The promoter used to drive guide RNA can include:

Pol III promoters such as U6 or H1 Use of Pol II promoter and intronic cassettes to express gRNA

Adeno Associated Virus (AAV)

Cpf1 and one or more guide RNA can be delivered using adeno associated virus (AAV), lentivirus, adenovirus or other plasmid or viral vector types, in particular, using formulations and doses from, for example, U.S. Pat. No. 8,454,972 (formulations, doses for adenovirus), U.S. Pat. No. 8,404,658 (formulations, doses for AAV) and U.S. Pat. No. 5,846,946 (formulations, doses for DNA plasmids) and from clinical trials and publications regarding the clinical trials involving lentivirus, AAV and adenovirus. For examples, for AAV, the route of administration, formulation and dose can be as in U.S. Pat. No. 8,454,972 and as in clinical trials involving AAV. For Adenovirus, the route of administration, formulation and dose can be as in U.S. Pat. No. 8,404,658 and as in clinical trials involving adenovirus. For plasmid delivery, the route of administration, formulation and dose can be as in U.S. Pat. No. 5,846,946 and as in clinical studies involving plasmids. Doses may be based on or extrapolated to an average 70 kg individual (e.g. a male adult human), and can be adjusted for patients, subjects, mammals of different weight and species. Frequency of administration is within the ambit of the medical or veterinary practitioner (e.g., physician, veterinarian), depending on usual factors including the age, sex, general health, other conditions of the patient or subject and the particular condition or symptoms being addressed. The viral vectors can be injected into the tissue of interest. For cell-type specific genome modification, the expression of Cpf1 can be driven by a cell-type specific promoter. For example, liver-specific expression might use the Albumin promoter and neuron-specific expression (e.g. for targeting CNS disorders) might use the Synapsin I promoter.

In terms of in vivo delivery, AAV is advantageous over other viral vectors for a couple of reasons:

Low toxicity (this may be due to the purification method not requiring ultra centrifugation of cell particles that can activate the immune response) and Low probability of causing insertional mutagenesis because it doesn't integrate into the host genome.

AAV has a packaging limit of 4.5 or 4.75 Kb. This means that Cpf1 as well as a promoter and transcription terminator have to be all fit into the same viral vector. Constructs larger than 4.5 or 4.75 Kb will lead to significantly reduced virus production. SpCas9 is quite large, the gene itself is over 4.1 Kb, which makes it difficult for packing into AAV. Therefore embodiments of the invention include utilizing homologs of Cpf1 that are shorter. For example:

rAAV vectors are preferably produced in insect cells, e.g., Spodoptera frugiperda Sf9 insect cells, grown in serum-free suspension culture. Serum-free insect cells can be purchased from commercial vendors, e.g., Sigma Aldrich (EX-CELL 405).

These species are therefore, in general, preferred Cpf1 species.

As to AAV, the AAV can be AAV1, AAV2, AAV5 or any combination thereof. One can select the AAV of the AAV with regard to the cells to be targeted; e.g., one can select AAV serotypes 1, 2, 5 or a hybrid capsid AAV1, AAV2, AAV5 or any combination thereof for targeting brain or neuronal cells; and one can select AAV4 for targeting cardiac tissue. AAV8 is useful for delivery to the liver. The herein promoters and vectors are preferred individually. A tabulation of certain AAV serotypes as to these cells (see Grimm, D. et al, J. Virol. 82: 5887-5911 (2008)) is as follows:

Lentivirus

Lentiviruses are complex retroviruses that have the ability to infect and express their genes in both mitotic and post-mitotic cells. The most commonly known lentivirus is the human immunodeficiency virus (HIV), which uses the envelope glycoproteins of other viruses to target a broad range of cell types.

Lentiviruses may be prepared as follows. After cloning pCasES10 (which contains a lentiviral transfer plasmid backbone), HEK293FT at low passage (p=5) were seeded in a T-75 flask to 50% confluence the day before transfection in DMEM with 10% fetal bovine serum and without antibiotics. After 20 hours, media was changed to OptiMEM (serum-free) media and transfection was done 4 hours later. Cells were transfected with 10 μg of lentiviral transfer plasmid (pCasES10) and the following packaging plasmids: 5 μg of pMD2.G (VSV-g pseudotype), and 7.5 μg of psPAX2 (gag/pol/rev/tat). Transfection was done in 4 mL OptiMEM with a cationic lipid delivery agent (50 μL Lipofectamine 2000 and 100 μl Plus reagent). After 6 hours, the media was changed to antibiotic-free DMEM with 10% fetal bovine serum. These methods use serum during cell culture, but serum-free methods are preferred.

Lentivirus may be purified as follows. Viral supernatants were harvested after 48 hours. Supernatants were first cleared of debris and filtered through a 0.45 μm low protein binding (PVDF) filter. They were then spun in a ultracentrifuge for 2 hours at 24,000 rpm. Viral pellets were resuspended in 50 μl of DMEM overnight at 4 C. They were then aliquoted and immediately frozen at −80° C.

In another embodiment, minimal non-primate lentiviral vectors based on the equine infectious anemia virus (EIAV) are also contemplated, especially for ocular gene therapy (see, e.g., Balagaan, J Gene Med 2006; 8: 275-285). In another embodiment, RetinoStat®, an equine infectious anemia virus-based lentiviral gene therapy vector that expresses angiostatic proteins endostatin and angiostatin that is delivered via a subretinal injection for the treatment of the web form of age-related macular degeneration is also contemplated (see, e.g., Binley et al., HUMAN GENE THERAPY 23:980-991 (September 2012)) and this vector may be modified for the CRISPR-Cas system of the present invention.

In another embodiment, self-inactivating lentiviral vectors with an siRNA targeting a common exon shared by HIV tat/rev, a nucleolar-localizing TAR decoy, and an anti-CCR5-specific hammerhead ribozyme (see, e.g., DiGiusto et al. (2010) Sci Transl Med 2:36ra43) may be used/and or adapted to the CRISPR-Cas system of the present invention. A minimum of 2.5×106 CD34+ cells per kilogram patient weight may be collected and prestimulated for 16 to 20 hours in X-VIVO 15 medium (Lonza) containing 2 μmol/L-glutamine, stem cell factor (100 ng/ml), Flt-3 ligand (Flt-3L) (100 ng/ml), and thrombopoietin (10 ng/ml) (CellGenix) at a density of 2×106 cells/ml. Prestimulated cells may be transduced with lentiviral at a multiplicity of infection of 5 for 16 to 24 hours in 75-cm2 tissue culture flasks coated with fibronectin (25 mg/cm2) (RetroNectin,Takara Bio Inc.).

Lentiviral vectors have been disclosed as in the treatment for Parkinson's Disease, see, e.g., US Patent Publication No. 20120295960 and U.S. Pat. Nos. 7,303,910 and 7,351,585. Lentiviral vectors have also been disclosed for the treatment of ocular diseases, see e.g., US Patent Publication Nos. 20060281180, 20090007284, US20110117189; US20090017543; US20070054961, US20100317109. Lentiviral vectors have also been disclosed for delivery to the brain, see, e.g., US Patent Publication Nos. US20110293571; US20110293571, US20040013648, US20070025970, US20090111106 and U.S. Pat. No. 7,259,015.

Use of Minimal Promoters

The present application provides a vector for delivering an effector protein and at least one CRISPR guide RNA to a cell comprising a minimal promoter operably linked to a polynucleotide sequence encoding the effector protein and a second minimal promoter operably linked to a polynucleotide sequence encoding at least one guide RNA, wherein the length of the vector sequence comprising the minimal promoters and polynucleotide sequences is less than 4.4Kb. In an embodiment, the vector is an AAV vector. In another embodiment, the effector protein is a CRISPR enzyme. In a further embodiment, the CRISPR enzyme is SaCas9, Cpf1, Cas13b or C2c2.

In a related aspect, the invention provides a lentiviral vector for delivering an effector protein and at least one CRISPR guide RNA to a cell comprising a promoter operably linked to a polynucleotide sequence encoding Cpf1 and a second promoter operably linked to a polynucleotide sequence encoding at least one guide RNA, wherein the polynucleotide sequences are in reverse orientation.

In another aspect, the invention provides a method of expressing an effector protein and guide RNA in a cell comprising introducing the vector according any of the vector delivery systems disclosed herein. In an embodiment of the vector for delivering an effector protein, the minimal promoter is the Mecp2 promoter, tRNA promoter, or U6. In a further embodiment, the minimal promoter is tissue specific.

Dosage of Vectors

In some embodiments, the vector, e.g., plasmid or viral vector is delivered to the tissue of interest by, for example, an intramuscular injection, while other times the delivery is via intravenous, transdermal, intranasal, oral, mucosal, or other delivery methods. Such delivery may be either via a single dose, or multiple doses. One skilled in the art understands that the actual dosage to be delivered herein may vary greatly depending upon a variety of factors, such as the vector choice, the target cell, organism, or tissue, the general condition of the subject to be treated, the degree of transformation/modification sought, the administration route, the administration mode, the type of transformation/modification sought, etc.

Such a dosage may further contain, for example, a carrier (water, saline, ethanol, glycerol, lactose, sucrose, calcium phosphate, gelatin, dextran, agar, pectin, peanut oil, sesame oil, etc.), a diluent, a pharmaceutically-acceptable carrier (e.g., phosphate-buffered saline), a pharmaceutically-acceptable excipient, and/or other compounds known in the art. The dosage may further contain one or more pharmaceutically acceptable salts such as, for example, a mineral acid salt such as a hydrochloride, a hydrobromide, a phosphate, a sulfate, etc.; and the salts of organic acids such as acetates, propionates, malonates, benzoates, etc. Additionally, auxiliary substances, such as wetting or emulsifying agents, pH buffering substances, gels or gelling materials, flavorings, colorants, microspheres, polymers, suspension agents, etc. may also be present herein. In addition, one or more other conventional pharmaceutical ingredients, such as preservatives, humectants, suspending agents, surfactants, antioxidants, anticaking agents, fillers, chelating agents, coating agents, chemical stabilizers, etc. may also be present, especially if the dosage form is a reconstitutable form. Suitable exemplary ingredients include microcrystalline cellulose, carboxymethylcellulose sodium, polysorbate 80, phenylethyl alcohol, chlorobutanol, potassium sorbate, sorbic acid, sulfur dioxide, propyl gallate, the parabens, ethyl vanillin, glycerin, phenol, parachlorophenol, gelatin, albumin and a combination thereof. A thorough discussion of pharmaceutically acceptable excipients is available in REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Pub. Co., N.J. 1991) which is incorporated by reference herein.

In an embodiment herein the delivery is via an adenovirus, which may be at a single booster dose containing at least 1×10 5 particles (also referred to as particle units, pu) of adenoviral vector. In an embodiment herein, the dose preferably is at least about 1×10 6 particles (for example, about 1×10 6 -1×10 12 particles), more preferably at least about 1×10 7 particles, more preferably at least about 1×10 8 particles (e.g., about 1×10 8 -1×10 11 particles or about 1×10 8 -1×10 12 particles), and most preferably at least about 1×10° particles (e.g., about 1×10 9 -1×10 10 particles or about 1×10 9 -1×10 12 particles), or even at least about 1×10 10 particles (e.g., about 1×10 10 -1×10 12 particles) of the adenoviral vector. Alternatively, the dose comprises no more than about 1×10 14 particles, preferably no more than about 1×10 13 particles, even more preferably no more than about 1×10 12 particles, even more preferably no more than about 1×10 11 particles, and most preferably no more than about 1×10 10 particles (e.g., no more than about 1×10 9 articles). Thus, the dose may contain a single dose of adenoviral vector with, for example, about 1×10 6 particle units (pu), about 2×10 6 pu, about 4×10 6 pu, about 1×10 7 pu, about 2×10 7 pu, about 4×10 7 pu, about 1×10 8 pu, about 2×10 8 pu, about 4×10 8 pu, about 1×10 9 pu, about 2×10 9 pu, about 4×10 9 pu, about 1×10 10 pu, about 2×10 10 pu, about 4×10 10 pu, about 1×10 11 pu, about 2×10 11 pu, about 4×10 11 pu, about 1×10 12 pu, about 2×10 12 pu, or about 4×10 12 pu of adenoviral vector. See, for example, the adenoviral vectors in U.S. Pat. No. 8,454,972 B2 to Nabel, et. al., granted on Jun. 4, 2013; incorporated by reference herein, and the dosages at col 29, lines 36-58 thereof. In an embodiment herein, the adenovirus is delivered via multiple doses.

In an embodiment herein, the delivery is via an AAV. A therapeutically effective dosage for in vivo delivery of the AAV to a human is believed to be in the range of from about 20 to about 50 ml of saline solution containing from about 1×10 10 to about 1×10 10 functional AAV/ml solution. The dosage may be adjusted to balance the therapeutic benefit against any side effects. In an embodiment herein, the AAV dose is generally in the range of concentrations of from about 1×10 5 to 1×10 50 genomes AAV, from about 1×10 8 to 1×10 20 genomes AAV, from about 1×10 10 to about 1×10 16 genomes, or about 1×10 11 to about 1×10 16 genomes AAV. A human dosage may be about 1×10 13 genomes AAV. Such concentrations may be delivered in from about 0.001 ml to about 100 ml, about 0.05 to about 50 ml, or about 10 to about 25 ml of a carrier solution. Other effective dosages can be readily established by one of ordinary skill in the art through routine trials establishing dose response curves. See, for example, U.S. Pat. No. 8,404,658 B2 to Hajjar, et al., granted on Mar. 26, 2013, at col. 27, lines 45-60.

In an embodiment herein the delivery is via a plasmid. In such plasmid compositions, the dosage should be a sufficient amount of plasmid to elicit a response. For instance, suitable quantities of plasmid DNA in plasmid compositions can be from about 0.1 to about 2 mg, or from about 1 μg to about 10 μg per 70 kg individual. Plasmids of the invention will generally comprise (i) a promoter; (ii) a sequence encoding a CRISPR enzyme, operably linked to said promoter; (iii) a selectable marker; (iv) an origin of replication; and (v) a transcription terminator downstream of and operably linked to (ii). The plasmid can also encode the RNA components of a CRISPR complex, but one or more of these may instead be encoded on a different vector.

The doses herein are based on an average 70 kg individual. The frequency of administration is within the ambit of the medical or veterinary practitioner (e.g., physician, veterinarian), or scientist skilled in the art. It is also noted that mice used in experiments are typically about 20 g and from mice experiments one can scale up to a 70 kg individual.

The dosage used for the compositions provided herein include dosages for repeated administration or repeat dosing. In particular embodiments, the administration is repeated within a period of several weeks, months, or years. Suitable assays can be performed to obtain an optimal dosage regime. Repeated administration can allow the use of lower dosage, which can positively affect off-target modifications.

RNA Delivery

In particular embodiments, RNA based delivery is used. In these embodiments, mRNA of the CRISPR effector protein is delivered together with in vitro transcribed guide RNA. Liang et al. describes efficient genome editing using RNA based delivery (Protein Cell. 2015 May; 6(5): 363-372).

RNA delivery: The CRISPR enzyme, for instance a Cpf1, and/or any of the present RNAs, for instance a guide RNA, can also be delivered in the form of RNA. Cpf1 mRNA can be generated using in vitro transcription. For example, Cpf1 mRNA can be synthesized using a PCR cassette containing the following elements: T7promoter-kozak sequence (GCCACC)-Cpf1-3′ UTR from beta globin-polyA tail (a string of 120 or more adenines). The cassette can be used for transcription by T7 polymerase. Guide RNAs can also be transcribed using in vitro transcription from a cassette containing T7 promoter-GG-guide RNA sequence.

To enhance expression and reduce possible toxicity, the CRISPR enzyme-coding sequence and/or the guide RNA can be modified to include one or more modified nucleoside e.g. using pseudo-U or 5-Methyl-C.

mRNA delivery methods are especially promising for liver delivery currently.

Much clinical work on RNA delivery has focused on RNAi or antisense, but these systems can be adapted for delivery of RNA for implementing the present invention. References below to RNAi etc. should be read accordingly.

CRISPR enzyme mRNA and guide RNA might also be delivered separately. CRISPR enzyme mRNA can be delivered prior to the guide RNA to give time for CRISPR enzyme to be expressed. CRISPR enzyme mRNA might be administered 1-12 hours (preferably around 2-6 hours) prior to the administration of guide RNA.

Alternatively, CRISPR enzyme mRNA and guide RNA can be administered together. Advantageously, a second booster dose of guide RNA can be administered 1-12 hours (preferably around 2-6 hours) after the initial administration of CRISPR enzyme mRNA+guide RNA.

In particular embodiments, pre-complexed guide RNA and CRISPR effector protein are delivered as a ribonucleoprotein (RNP). RNPs have the advantage that they lead to rapid editing effects even more so than the RNA method because this process avoids the need for transcription. An important advantage is that both RNP delivery is transient, reducing off-target effects and toxicity issues. Efficient genome editing in different cell types has been observed by Kim et al. (2014, Genome Res. 24(6):1012-9), Paix et al. (2015, Genetics 204(1):47-54), Chu et al. (2016, BMC Biotechnol. 16:4), and Wang et al. (2013, Cell. 9; 153(4):910-8).

In particular embodiments, the ribonucleoprotein is delivered by way of a polypeptide-based shuttle agent as described in WO2016161516. WO2016161516 describes efficient transduction of polypeptide cargos using synthetic peptides comprising an endosome leakage domain (ELD) operably linked to a cell penetrating domain (CPD), to a histidine-rich domain and a CPD. Similarly these polypeptides can be used for the delivery of CRISPR-effector based RNPs in eukaryotic cells.

Indeed, RNA delivery is a useful method of in vivo delivery. It is possible to deliver Cpf1 and gRNA (and, for instance, HR repair template) into cells using liposomes or particles. Thus delivery of the CRISPR enzyme, such as a Cpf1 and/or delivery of the RNAs of the invention may be in RNA form and via microvesicles, liposomes or particles. For example, Cpf1 mRNA and gRNA can be packaged into liposomal particles for delivery in vivo. Liposomal transfection reagents such as lipofectamine from Life Technologies and other reagents on the market can effectively deliver RNA molecules into the liver.

Means of delivery of RNA also preferred include delivery of RNA via nanoparticles (Cho, S., Goldberg, M., Son, S., Xu, Q., Yang, F., Mei, Y., Bogatyrev, S., Langer, R. and Anderson, D., Lipid-like nanoparticles for small interfering RNA delivery to endothelial cells, Advanced Functional Materials, 19: 3112-3118, 2010) or exosomes (Schroeder, A., Levins, C., Cortez, C., Langer, R., and Anderson, D., Lipid-based nanotherapeutics for siRNA delivery, Journal of Internal Medicine, 267: 9-21, 2010, PMID: 20059641). Indeed, exosomes have been shown to be particularly useful in delivery siRNA, a system with some parallels to the CRISPR system. For instance, El-Andaloussi S, et al. (“Exosome-mediated delivery of siRNA in vitro and in vivo.” Nat Protoc. 2012 December; 7(12):2112-26. doi: 10.1038/nprot.2012.131. Epub 2012 Nov. 15.) describe how exosomes are promising tools for drug delivery across different biological barriers and can be harnessed for delivery of siRNA in vitro and in vivo. Their approach is to generate targeted exosomes through transfection of an expression vector, comprising an exosomal protein fused with a peptide ligand. The exosomes are then purify and characterized from transfected cell supernatant, then RNA is loaded into the exosomes. Delivery or administration according to the invention can be performed with exosomes, in particular but not limited to the brain. Vitamin E (α-tocopherol) may be conjugated with CRISPR-Cas and delivered to the brain along with high density lipoprotein (HDL), for example in a similar manner as was done by Uno et al. (HUMAN GENE THERAPY 22:711-719 (June 2011)) for delivering short-interfering RNA (siRNA) to the brain. Mice were infused via Osmotic minipumps (model 1007D; Alzet, Cupertino, Calif.) filled with phosphate-buffered saline (PBS) or free TocsiBACE or Toc-siBACE/HDL and connected with Brain Infusion Kit 3 (Alzet). A brain-infusion cannula was placed about 0.5 mM posterior to the bregma at midline for infusion into the dorsal third ventricle. Uno et al. found that as little as 3 nmol of Toc-siRNA with HDL could induce a target reduction in comparable degree by the same ICV infusion method. A similar dosage of CRISPR-Cas conjugated to α-tocopherol and co-administered with HDL targeted to the brain may be contemplated for humans in the present invention, for example, about 3 nmol to about 3 μmol of CRISPR-Cas targeted to the brain may be contemplated.

Zou et al. ((HUMAN GENE THERAPY 22:465-475 (April 2011)) describes a method of lentiviral-mediated delivery of short-hairpin RNAs targeting PKCγ for in vivo gene silencing in the spinal cord of rats. Zou et al. administered about 10 μl of a recombinant lentivirus having a titer of 1×109 transducing units (TU)/ml by an intrathecal catheter. A similar dosage of CRISPR-Cas expressed in a lentiviral vector may be contemplated for humans in the present invention, for example, about 10-50 ml of CRISPR-Cas in a lentivirus having a titer of 1×109 transducing units (TU)/ml may be contemplated. A similar dosage of CRISPR-Cas expressed in a lentiviral vector targeted to the brain may be contemplated for humans in the present invention, for example, about 10-50 ml of CRISPR-Cas targeted to the brain in a lentivirus having a titer of 1×109 transducing units (TU)/ml may be contemplated.

Anderson et al. (US 20170079916) provides a modified dendrimer nanoparticle for the delivery of therapeutic, prophylactic and/or diagnostic agents to a subject, comprising: one or more zero to seven generation alkylated dendrimers; one or more amphiphilic polymers; and one or more therapeutic, prophylactic and/or diagnostic agents encapsulated therein. One alkylated dendrimer may be selected from the group consisting of poly(ethyleneimine), poly (polypropylenimine), diaminobutane amine polypropylenimine tetramine and poly(amido amine). The therapeutic, prophylactic and diagnostic agent may be selected from the group consisting of proteins, peptides, carbohydrates, nucleic acids, lipids, small molecules and combinations thereof

Anderson et al. (US 20160367686) provides a compound of Formula (I):

and salts thereof, wherein each instance of R L is independently optionally substituted C6-C40 alkenyl, and a composition for the delivery of an agent to a subject or cell comprising the compound, or a salt thereof; an agent; and optionally, an excipient. The agent may be an organic molecule, inorganic molecule, nucleic acid, protein, peptide, polynucleotide, targeting agent, an isotopically labeled chemical compound, vaccine, an immunological agent, or an agent useful in bioprocessing. The composition may further comprise cholesterol, a PEGylated lipid, a phospholipid, or an apolipoprotein.

Anderson et al. (US20150232883) provides a delivery particle formulations and/or systems, preferably nanoparticle delivery formulations and/or systems, comprising (a) a CRISPR-Cas system RNA polynucleotide sequence; or (b) Cas9; or (c) both a CRISPR-Cas system RNA polynucleotide sequence and Cas9; or (d) one or more vectors that contain nucleic acid molecule(s) encoding (a), (b) or (c), wherein the CRISPR-Cas system RNA polynucleotide sequence and the Cas9 do not naturally occur together. The delivery particle formulations may further comprise a surfactant, lipid or protein, wherein the surfactant may comprise a cationic lipid.

Anderson et al. (US20050123596) provides examples of microparticles that are designed to release their payload when exposed to acidic conditions, wherein the microparticles comprise at least one agent to be delivered, a pH triggering agent, and a polymer, wherein the polymer is selected from the group of polymethacrylates and polyacrylates.

Anderson et al (US 20020150626) provides lipid-protein-sugar particles for delivery of nucleic acids, wherein the polynucleotide is encapsulated in a lipid-protein-sugar matrix by contacting the polynucleotide with a lipid, a protein, and a sugar; and spray drying mixture of the polynucleotide, the lipid, the protein, and the sugar to make microparticles.

In terms of local delivery to the brain, this can be achieved in various ways. For instance, material can be delivered intrastriatally e.g. by injection. Injection can be performed stereotactically via a craniotomy.

Enhancing NHEJ or HR efficiency is also helpful for delivery. It is preferred that NHEJ efficiency is enhanced by co-expressing end-processing enzymes such as Trex2 (Dumitrache et al. Genetics. 2011 August; 188(4): 787-797). It is preferred that HR efficiency is increased by transiently inhibiting NHEJ machineries such as Ku70 and Ku86. HR efficiency can also be increased by co-expressing prokaryotic or eukaryotic homologous recombination enzymes such as RecBCD, RecA.

Particles

In some aspects or embodiments, a composition comprising a delivery particle formulation may be used. In some aspects or embodiments, the formulation comprises a CRISPR complex, the complex comprising a CRISPR protein and-a guide which directs sequence-specific binding of the CRISPR complex to a target sequence. In some embodiments, the delivery particle comprises a lipid-based particle, optionally a lipid nanoparticle, or cationic lipid and optionally biodegradable polymer. In some embodiments, the cationic lipid comprises 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). In some embodiments, the hydrophilic polymer comprises ethylene glycol or polyethylene glycol. In some embodiments, the delivery particle further comprises a lipoprotein, preferably cholesterol. In some embodiments, the delivery particles are less than 500 nm in diameter, optionally less than 250 nm in diameter, optionally less than 100 nm in diameter, optionally about 35 nm to about 60 nm in diameter.

Several types of particle delivery systems and/or formulations are known to be useful in a diverse spectrum of biomedical applications. In general, a particle is defined as a small object that behaves as a whole unit with respect to its transport and properties. Particles are further classified according to diameter. Coarse particles cover a range between 2,500 and 10,000 nanometers. Fine particles are sized between 100 and 2,500 nanometers. Ultrafine particles, or nanoparticles, are generally between 1 and 100 nanometers in size. The basis of the 100 nm limit is the fact that novel properties that differentiate particles from the bulk material typically develop at a critical length scale of under 100 nm.

As used herein, a particle delivery system/formulation is defined as any biological delivery system/formulation which includes a particle in accordance with the present invention. A particle in accordance with the present invention is any entity having a greatest dimension (e.g. diameter) of less than 100 microns (μm). In some embodiments, inventive particles have a greatest dimension of less than 10 μm. In some embodiments, inventive particles have a greatest dimension of less than 2000 nanometers (nm). In some embodiments, inventive particles have a greatest dimension of less than 1000 nanometers (nm). In some embodiments, inventive particles have a greatest dimension of less than 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, or 100 nm. Typically, inventive particles have a greatest dimension (e.g., diameter) of 500 nm or less. In some embodiments, inventive particles have a greatest dimension (e.g., diameter) of 250 nm or less. In some embodiments, inventive particles have a greatest dimension (e.g., diameter) of 200 nm or less. In some embodiments, inventive particles have a greatest dimension (e.g., diameter) of 150 nm or less. In some embodiments, inventive particles have a greatest dimension (e.g., diameter) of 100 nm or less. Smaller particles, e.g., having a greatest dimension of 50 nm or less are used in some embodiments of the invention. In some embodiments, inventive particles have a greatest dimension ranging between 25 nm and 200 nm.

In terms of this invention, it is preferred to have one or more components of CRISPR complex, e.g., CRISPR enzyme or mRNA or guide RNA delivered using nanoparticles or lipid envelopes. Other delivery systems or vectors are may be used in conjunction with the nanoparticle aspects of the invention.

In general, a “nanoparticle” refers to any particle having a diameter of less than 1000 nm. In certain preferred embodiments, nanoparticles of the invention have a greatest dimension (e.g., diameter) of 500 nm or less. In other preferred embodiments, nanoparticles of the invention have a greatest dimension ranging between 25 nm and 200 nm. In other preferred embodiments, nanoparticles of the invention have a greatest dimension of 100 nm or less. In other preferred embodiments, nanoparticles of the invention have a greatest dimension ranging between 35 nm and 60 nm. It will be appreciated that reference made herein to particles or nanoparticles can be interchangeable, where appropriate.

It will be understood that the size of the particle will differ depending as to whether it is measured before or after loading. Accordingly, in particular embodiments, the term “nanoparticles” may apply only to the particles pre loading.

Nanoparticles encompassed in the present invention may be provided in different forms, e.g., as solid nanoparticles (e.g., metal such as silver, gold, iron, titanium), non-metal, lipid-based solids, polymers), suspensions of nanoparticles, or combinations thereof. Metal, dielectric, and semiconductor nanoparticles may be prepared, as well as hybrid structures (e.g., core-shell nanoparticles). Nanoparticles made of semiconducting material may also be labeled quantum dots if they are small enough (typically sub 10 nm) that quantization of electronic energy levels occurs. Such nanoscale particles are used in biomedical applications as drug carriers or imaging agents and may be adapted for similar purposes in the present invention.

Semi-solid and soft nanoparticles have been manufactured, and are within the scope of the present invention. A prototype nanoparticle of semi-solid nature is the liposome. Various types of liposome nanoparticles are currently used clinically as delivery systems for anticancer drugs and vaccines. Nanoparticles with one half hydrophilic and the other half hydrophobic are termed Janus particles and are particularly effective for stabilizing emulsions. They can self-assemble at water/oil interfaces and act as solid surfactants.

Particle characterization (including e.g., characterizing morphology, dimension, etc.) is done using a variety of different techniques. Common techniques are electron microscopy (TEM, SEM), atomic force microscopy (AFM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF), ultraviolet-visible spectroscopy, dual polarization interferometry and nuclear magnetic resonance (NMR). Characterization (dimension measurements) may be made as to native particles (i.e., preloading) or after loading of the cargo (herein cargo refers to e.g., one or more components of CRISPR-Cas system e.g., CRISPR enzyme or mRNA or guide RNA, or any combination thereof, and may include additional carriers and/or excipients) to provide particles of an optimal size for delivery for any in vitro, ex vivo and/or in vivo application of the present invention. In certain preferred embodiments, particle dimension (e.g., diameter) characterization is based on measurements using dynamic laser scattering (DLS). Mention is made of U.S. Pat. Nos. 8,709,843; 6,007,845; 5,855,913; 5,985,309; 5,543,158; and the publication by James E. Dahlman and Carmen Barnes et al. Nature Nanotechnology (2014) published online 11 May 2014, doi:10.1038/nnano.2014.84, concerning particles, methods of making and using them and measurements thereof.

Particles delivery systems within the scope of the present invention may be provided in any form, including but not limited to solid, semi-solid, emulsion, or colloidal particles. As such any of the delivery systems described herein, including but not limited to, e.g., lipid-based systems, liposomes, micelles, microvesicles, exosomes, or gene gun may be provided as particle delivery systems within the scope of the present invention.

CRISPR enzyme mRNA and guide RNA may be delivered simultaneously using particles or lipid envelopes; for instance, CRISPR enzyme and RNA of the invention, e.g., as a complex, can be delivered via a particle as in Dahlman et al., WO2015089419 A2 and documents cited therein, such as 7C1 (see, e.g., James E. Dahlman and Carmen Barnes et al. Nature Nanotechnology (2014) published online 11 May 2014, doi:10.1038/nnano 2014.84), e.g., delivery particle comprising lipid or lipidoid and hydrophilic polymer, e.g., cationic lipid and hydrophilic polymer, for instance wherein the cationic lipid comprises 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or 1,2-ditetradecanoyl-sn-glycero-3-phosphocholine (DMPC) and/or wherein the hydrophilic polymer comprises ethylene glycol or polyethylene glycol (PEG); and/or wherein the particle further comprises cholesterol (e.g., particle from formulation 1=DOTAP 100, DMPC 0, PEG 0, Cholesterol 0; formulation number 2=DOTAP 90, DMPC 0, PEG 10, Cholesterol 0; formulation number 3=DOTAP 90, DMPC 0, PEG 5, Cholesterol 5), wherein particles are formed using an efficient, multistep process wherein first, effector protein and RNA are mixed together, e.g., at a 1:1 molar ratio, e.g., at room temperature, e.g., for 30 minutes, e.g., in sterile, nuclease free 1×PBS; and separately, DOTAP, DMPC, PEG, and cholesterol as applicable for the formulation are dissolved in alcohol, e.g., 100% ethanol; and, the two solutions are mixed together to form particles containing the complexes).

Nucleic acid-targeting effector proteins (such as a Type V protein such Cpf1) mRNA and guide RNA may be delivered simultaneously using particles or lipid envelopes. Examples of suitable particles include but are not limited to those described in U.S. Pat. No. 9,301,923.

For example, Su X, Fricke J, Kavanagh D G, Irvine D J (“In vitro and in vivo mRNA delivery using lipid-enveloped pH-responsive polymer nanoparticles” Mol Pharm. 2011 Jun. 6; 8(3):774-87. doi: 10.1021/mp100390w. Epub 2011 Apr. 1) describes biodegradable core-shell structured nanoparticles with a poly(β-amino ester) (PBAE) core enveloped by a phospholipid bilayer shell. These were developed for in vivo mRNA delivery. The pH-responsive PBAE component was chosen to promote endosome disruption, while the lipid surface layer was selected to minimize toxicity of the polycation core. Such are, therefore, preferred for delivering RNA of the present invention.

Liu et al. (US 20110212179) provides bimodal porous polymer microspheres comprising a base polymer, wherein the particle comprises macropores having a diameter ranging from about 20 to about 500 microns and micropores having a diameter ranging from about 1 to about 70 microns, and wherein the microspheres have a diameter ranging from about 50 to about 1100 microns.

Berg et al. (US20160174546) a nanolipid delivery system, in particular a nano-particle concentrate, comprising: a composition comprising a lipid, oil or solvent, the composition having a viscosity of less than 100 cP at 25.degree. C. and a Kauri Butanol solvency of greater than 25 Kb; and at least one amphipathic compound selected from the group consisting of an alkoxylated lipid, an alkoxylated fatty acid, an alkoxylated alcohol, a heteroatomic hydrophilic lipid, a heteroatomic hydrophilic fatty acid, a heteroatomic hydrophilic alcohol, a diluent, and combinations thereof, wherein the compound is derived from a starting compound having a viscosity of less than 1000 cP at 50.degree. C., wherein the concentrate is configured to provide a stable nano emulsion having a D50 and a mean average particle size distribution of less than 100 nm when diluted.

Liu et al. (US 20140301951) provides a protocell nanostructure comprising: a porous particle core comprising a plurality of pores; and at least one lipid bilayer surrounding the porous particle core to form a protocell, wherein the protocell is capable of loading one or more cargo components to the plurality of pores of the porous particle core and releasing the one or more cargo components from the porous particle core across the surrounding lipid bilayer.

Chromy et al. (US 20150105538) provides methods and systems for assembling, solubilizing and/or purifying a membrane associated protein in a nanolipoprotein particle, which comprise a temperature transition cycle performed in presence of a detergent, wherein during the temperature transition cycle the nanolipoprotein components are brought to a temperature above and below the gel to liquid crystalling transition temperature of the membrane forming lipid of the nanolipoprotein particle.

Bader et al. (US 20150250725), provides a method for producing a lipid particle comprising the following: i) providing a first solution comprising denatured apolipoprotein, ii) adding the first solution to a second solution comprising at least two lipids and a detergent but no apolipoprotein, and iii) removing the detergent from the solution obtained in ii) and thereby producing a lipid particle.

Mirkin et al., (US20100129793) provides a method of preparing a composite particle comprising the steps of (a) admixing a dielectric component and a magnetic component to form a first intermediate, (b) admixing the first intermediate and gold seeds to form a second intermediate, and (c) forming a gold shell on the second intermediate by admixing the second intermediate with a gold source and a reducing agent to form said composite particle.

In one embodiment, particles/nanoparticles based on self assembling bioadhesive polymers are contemplated, which may be applied to oral delivery of peptides, intravenous delivery of peptides and nasal delivery of peptides, all to the brain. Other embodiments, such as oral absorption and ocular delivery of hydrophobic drugs are also contemplated. The molecular envelope technology involves an engineered polymer envelope which is protected and delivered to the site of the disease (see, e.g., Mazza, M. et al. ACSNano, 2013. 7(2): 1016-1026; Siew, A., et al. Mol Pharm, 2012. 9(1):14-28; Lalatsa, A., et al. J Contr Rel, 2012. 161(2):523-36; Lalatsa, A., et al., Mol Pharm, 2012. 9(6):1665-80; Lalatsa, A., et al. Mol Pharm, 2012. 9(6):1764-74; Garrett, N. L., et al. J Biophotonics, 2012. 5(5-6):458-68; Garrett, N. L., et al. J Raman Spect, 2012. 43(5):681-688; Ahmad, S., et al. J Royal Soc Interface 2010. 7:S423-33; Uchegbu, I. F. Expert Opin Drug Deliv, 2006. 3(5):629-40; Qu, X., et al. Biomacromolecules, 2006. 7(12):3452-9 and Uchegbu, I. F., et al. Int J Pharm, 2001. 224:185-199). Doses of about 5 mg/kg are contemplated, with single or multiple doses, depending on the target tissue.

In one embodiment, particles/nanoparticles that can deliver RNA to a cancer cell to stop tumor growth developed by Dan Anderson's lab at MIT may be used/and or adapted to the CRISPR-Cas system of the present invention. In particular, the Anderson lab developed fully automated, combinatorial systems for the synthesis, purification, characterization, and formulation of new biomaterials and nanoformulations. See, e.g., Alabi et al., Proc Natl Acad Sci USA. 2013 Aug. 6; 110(32):12881-6; Zhang et al., Adv Mater. 2013 Sep. 6; 25(33):4641-5; Jiang et al., Nano Lett. 2013 Mar. 13; 13(3):1059-64; Karagiannis et al., ACS Nano. 2012 Oct. 23; 6(10):8484-7; Whitehead et al., ACS Nano. 2012 Aug. 28; 6(8):6922-9 and Lee et al., Nat Nanotechnol. 2012 Jun. 3; 7(6):389-93.

The lipid particles developed by the Qiaobing Xu's lab at Tufts University may be used/adapted to the present delivery system for cancer therapy. See Wang et al., J. Control Release, 2017 Jan. 31. pii: 50168-3659(17)30038-X. doi: 10.1016/jjconre1.2017.01.037. [Epub ahead of print]; Altmoglu et al., Biomater Sci., 4(12):1773-80, Nov. 15, 2016; Wang et al., PNAS, 113(11):2868-73 Mar. 15, 2016; Wang et al., PloS One, 10(11): e0141860. doi: 10.1371/journal.pone.0141860. eCollection 2015, Nov. 3, 2015; Takeda et al., Neural Regen Res. 10(5):689-90, May 2015; Wang et al., Adv. Health Mater., 3(9):1398-403, September 2014; and Wang et al., Agnew Chem Int Ed Engl., 53(11):2893-8, Mar. 10, 2014.

US patent application 20110293703 relates to lipidoid compounds are also particularly useful in the administration of polynucleotides, which may be applied to deliver the CRISPR-Cas system of the present invention. In one aspect, the aminoalcohol lipidoid compounds are combined with an agent to be delivered to a cell or a subject to form microparticles, nanoparticles, liposomes, or micelles. The agent to be delivered by the particles, liposomes, or micelles may be in the form of a gas, liquid, or solid, and the agent may be a polynucleotide, protein, peptide, or small molecule. The aminoalcohol lipidoid compounds may be combined with other aminoalcohol lipidoid compounds, polymers (synthetic or natural), surfactants, cholesterol, carbohydrates, proteins, lipids, etc. to form the particles. These particles may then optionally be combined with a pharmaceutical excipient to form a pharmaceutical composition.

US Patent Publication No. 20110293703 also provides methods of preparing the aminoalcohol lipidoid compounds. One or more equivalents of an amine are allowed to react with one or more equivalents of an epoxide-terminated compound under suitable conditions to form an aminoalcohol lipidoid compound of the present invention. In certain embodiments, all the amino groups of the amine are fully reacted with the epoxide-terminated compound to form tertiary amines. In other embodiments, all the amino groups of the amine are not fully reacted with the epoxide-terminated compound to form tertiary amines thereby resulting in primary or secondary amines in the aminoalcohol lipidoid compound. These primary or secondary amines are left as is or may be reacted with another electrophile such as a different epoxide-terminated compound. As will be appreciated by one skilled in the art, reacting an amine with less than excess of epoxide-terminated compound will result in a plurality of different aminoalcohol lipidoid compounds with various numbers of tails. Certain amines may be fully functionalized with two epoxide-derived compound tails while other molecules will not be completely functionalized with epoxide-derived compound tails. For example, a diamine or polyamine may include one, two, three, or four epoxide-derived compound tails off the various amino moieties of the molecule resulting in primary, secondary, and tertiary amines. In certain embodiments, all the amino groups are not fully functionalized. In certain embodiments, two of the same types of epoxide-terminated compounds are used. In other embodiments, two or more different epoxide-terminated compounds are used. The synthesis of the aminoalcohol lipidoid compounds is performed with or without solvent, and the synthesis may be performed at higher temperatures ranging from 30-100° C., preferably at approximately 50-90° C. The prepared aminoalcohol lipidoid compounds may be optionally purified. For example, the mixture of aminoalcohol lipidoid compounds may be purified to yield an aminoalcohol lipidoid compound with a particular number of epoxide-derived compound tails. Or the mixture may be purified to yield a particular stereo- or regioisomer. The aminoalcohol lipidoid compounds may also be alkylated using an alkyl halide (e.g., methyl iodide) or other alkylating agent, and/or they may be acylated.

US Patent Publication No. 20110293703 also provides libraries of aminoalcohol lipidoid compounds prepared by the inventive methods. These aminoalcohol lipidoid compounds may be prepared and/or screened using high-throughput techniques involving liquid handlers, robots, microtiter plates, computers, etc. In certain embodiments, the aminoalcohol lipidoid compounds are screened for their ability to transfect polynucleotides or other agents (e.g., proteins, peptides, small molecules) into the cell.

US Patent Publication No. 20130302401 relates to a class of poly(beta-amino alcohols) (PBAAs) has been prepared using combinatorial polymerization. The inventive PBAAs may be used in biotechnology and biomedical applications as coatings (such as coatings of films or multilayer films for medical devices or implants), additives, materials, excipients, non-biofouling agents, micropatterning agents, and cellular encapsulation agents. When used as surface coatings, these PBAAs elicited different levels of inflammation, both in vitro and in vivo, depending on their chemical structures. The large chemical diversity of this class of materials allowed us to identify polymer coatings that inhibit macrophage activation in vitro. Furthermore, these coatings reduce the recruitment of inflammatory cells, and reduce fibrosis, following the subcutaneous implantation of carboxylated polystyrene microparticles. These polymers may be used to form polyelectrolyte complex capsules for cell encapsulation. The invention may also have many other biological applications such as antimicrobial coatings, DNA or siRNA delivery, and stem cell tissue engineering. The teachings of US Patent Publication No. 20130302401 may be applied to the CRISPR-Cas system of the present invention.

In another embodiment, lipid nanoparticles (LNPs) are contemplated. An antitransthyretin small interfering RNA has been encapsulated in lipid nanoparticles and delivered to humans (see, e.g., Coelho et al., N Engl J Med 2013; 369:819-29), and such a system may be adapted and applied to the CRISPR-Cas system of the present invention. Doses of about 0.01 to about 1 mg per kg of body weight administered intravenously are contemplated. Medications to reduce the risk of infusion-related reactions are contemplated, such as dexamethasone, acetaminophen, diphenhydramine or cetirizine, and ranitidine are contemplated. Multiple doses of about 0.3 mg per kilogram every 4 weeks for five doses are also contemplated.

Zhu et al. (US20140348900) provides for a process for preparing liposomes, lipid discs, and other lipid nanoparticles using a multi-port manifold, wherein the lipid solution stream, containing an organic solvent, is mixed with two or more streams of aqueous solution (e.g., buffer). In some aspects, at least some of the streams of the lipid and aqueous solutions are not directly opposite of each other. Thus, the process does not require dilution of the organic solvent as an additional step. In some embodiments, one of the solutions may also contain an active pharmaceutical ingredient (API). This invention provides a robust process of liposome manufacturing with different lipid formulations and different payloads. Particle size, morphology, and the manufacturing scale can be controlled by altering the port size and number of the manifold ports, and by selecting the flow rate or flow velocity of the lipid and aqueous solutions.

Cullis et al. (US 20140328759) provides limit size lipid nanoparticles with a diameter from 10-100 nm, in particular comprising a lipid bilayer surrounding an aqueous core. Methods and apparatus for preparing such limit size lipid nanoparticles are also disclosed.

Manoharan et al. (US 20140308304) provides cationic lipids of formula (I)

or a salt thereof, wherein X is N or P; R′ is absent, hydrogen, or alkyl; with respect to R 1 and R 2 , (i) R 1 and R 2 are each, independently, optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, heterocycle or R 10 ; (ii) R 1 and R 2 , together with the nitrogen atom to which they are attached, form an optionally substituted heterocylic ring; or (iii) one of R 1 and R 2 is optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, or heterocycle, and the other forms a 4-10 member heterocyclic ring or heteroaryl with (a) the adjacent nitrogen atom and (b) the (R) a group adjacent to the nitrogen atom; each occurrence of R is, independently, —(CR 3 R 4 )—; each occurrence of R 3 and R 4 are, independently H, halogen, OH, alkyl, alkoxy, —NH.sub.2, alkylamino, or dialkylamino; or R 3 and R 4 , together with the carbon atom to which they are directly attached, form a cycloalkyl group, wherein no more than three R groups in each chain attached to the atom X* are cycloalkyl; each occurrence of R.sup.10 is independently selected from PEG and polymers based on poly(oxazoline), poly(ethylene oxide), poly(vinyl alcohol), poly(glycerol), poly(N-vinylpyrrolidone), poly[N-(2-hydroxypropyl)methacrylamide] and poly(amino acid)s, wherein (i) the PEG or polymer is linear or branched, (ii) the PEG or polymer is polymerized by n subunits, (iii) n is a number-averaged degree of polymerization between 10 and 200 units, and (iv) wherein the compound of formula has at most two R 10 groups; Q is absent or is —O—, —NH—, —C(O)O—, —OC(O)—, —C(O)N(R 4 )—, —N(R 5 )C(O)—, —S—S—, —OC(O)O—, —O—N.dbd.C(R 5 )—, —C(R 5 ).dbd.N—O—, —OC(O)N(R 5 )—, —N(R 5 )C(O)N(R 5 )—, —N(R 5 )C(O)O—, —C(O)S—, —C(S)O— or —C(R 5 ).dbd.N—O—C(O)—; Q 1 and Q 2 are each, independently, absent, —O—, —OC(O)—, —C(O)O—, —SC(O)—, —C(O)S—, —OC(S)—, —C(S)O—, —S—S—, —C(O)(NR 5 )—, —N(R 5 )C(O)—, —C(S)(NR 5 )—, —N(R 5 )C(O)—, —N(R 5 )C(O)N(R 5 )—, or —OC(O)O—; Q 3 and Q 4 are each, independently, H, —(CR 3 R 4 )—, aryl, or a cholesterol moiety; each occurrence of A 1 , A 2 , A 3 and A 4 is, independently, —(CR 5 R 5 —CR 5 .dbd.CR 5 )—; each occurrence of R 5 is, independently, H or alkyl; M 1 and M 2 are each, independently, a biodegradable group (e.g., —OC(O)—, —C(O)O—, —SC(O)—, —C(O)S—, —OC(S)—, —C(S)O—, —S—S—, —C(R 5 ).dbd.N—, —N.dbd.C(R 5 )—, —C(R 5 ).dbd.N—O—, —O—N.dbd.C(R5)-, —C(O)(NR5)-, —N(R5)C(O)—, —C(S)(NR 5 )—, —N(R 5 )C(O)—, —N(R 5 )C(O)N(R 5 )—, —OC(O)O—, Si(R 5 ).sub.2O—, —C(O)(CR 3 R 4 )C(O)O—, or —OC(O)(CR 3 R 4 )C(O)—); Z is absent, alkylene or —O—P(O)(OH)—O—; each ------ attached to Z is an optional bond, such that when Z is absent, Q 3 and Q 4 are not directly covalently bound together; a is 1, 2, 3, 4, 5 or 6; b is 0, 1, 2, or 3; c, d, e, f, i, j, m, n, q and r are each, independently, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; g and h are each, independently, 0, 1 or 2; k and 1 are each, independently, 0 or 1, where at least one of k and 1 is 1; and o and p are each, independently, 0, 1 or 2, wherein Q 3 and Q 4 are each, independently, separated from the tertiary atom marked with an asterisk (X*) by a chain of 8 or more atoms. The cationic lipid can be used with other lipid components such as cholesterol and PEG-lipids to form lipid nanoparticles with oligonucleotides, to facilitate the cellular uptake and endosomal escape, and to knockdown target mRNA both in vitro and in vivo.

LNPs have been shown to be highly effective in delivering siRNAs to the liver (see, e.g., Tabernero et al., Cancer Discovery, April 2013, Vol. 3, No. 4, pages 363-470) and are therefore contemplated for delivering RNA encoding CRISPR-Cas to the liver. A dosage of about four doses of 6 mg/kg of the LNP every two weeks may be contemplated. Tabernero et al. demonstrated that tumor regression was observed after the first 2 cycles of LNPs dosed at 0.7 mg/kg, and by the end of 6 cycles the patient had achieved a partial response with complete regression of the lymph node metastasis and substantial shrinkage of the liver tumors. A complete response was obtained after 40 doses in this patient, who has remained in remission and completed treatment after receiving doses over 26 months. Two patients with RCC and extrahepatic sites of disease including kidney, lung, and lymph nodes that were progressing following prior therapy with VEGF pathway inhibitors had stable disease at all sites for approximately 8 to 12 months, and a patient with PNET and liver metastases continued on the extension study for 18 months (36 doses) with stable disease.

However, the charge of the LNP must be taken into consideration. As cationic lipids combined with negatively charged lipids to induce nonbilayer structures that facilitate intracellular delivery. Because charged LNPs are rapidly cleared from circulation following intravenous injection, ionizable cationic lipids with pKa values below 7 were developed (see, e.g., Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). Negatively charged polymers such as RNA may be loaded into LNPs at low pH values (e.g., pH 4) where the ionizable lipids display a positive charge. However, at physiological pH values, the LNPs exhibit a low surface charge compatible with longer circulation times. Four species of ionizable cationic lipids have been focused upon, namely 1,2-dilineoyl-3-dimethylammonium-propane (DLinDAP), 1,2-dilinoleyloxy-3-N,N-dimethylaminopropane (DLinDMA), 1,2-dilinoleyloxy-keto-N,N-dimethyl-3-aminopropane (DLinKDMA), and 1,2-dilinoleyl-4-(2-dimethylaminoethyl)-[1,3]-dioxolane (DLinKC2-DMA). It has been shown that LNP siRNA systems containing these lipids exhibit remarkably different gene silencing properties in hepatocytes in vivo, with potencies varying according to the series DLinKC2-DMA>DLinKDMA>DLinDMA>>DLinDAP employing a Factor VII gene silencing model (see, e.g., Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). A dosage of 1 μg/ml of LNP or CRISPR-Cas RNA in or associated with the LNP may be contemplated, especially for a formulation containing DLinKC2-DMA.

Preparation of LNPs and CRISPR-Cas encapsulation may be used/and or adapted from Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). The cationic lipids 1,2-dilineoyl-3-dimethylammonium-propane (DLinDAP), 1,2-dilinoleyloxy-3-N,N-dimethylaminopropane (DLinDMA), 1,2-dilinoleyloxyketo-N,N-dimethyl-3-aminopropane (DLinK-DMA), 1,2-dilinoleyl-4-(2-dimethylaminoethyl)-[1,3]-dioxolane (DLinKC2-DMA), (3-o-[2″-(methoxypolyethyleneglycol 2000) succinoyl]-1,2-dimyristoyl-sn-glycol (PEG-S-DMG), and R-3-1(ω-methoxy-poly(ethylene glycol)2000) carbamoyl]-1,2-dimyristyloxlpropyl-3-amine (PEG-C-DOMG) may be provided by Tekmira Pharmaceuticals (Vancouver, Canada) or synthesized. Cholesterol may be purchased from Sigma (St Louis, Mo.). The specific CRISPR-Cas RNA may be encapsulated in LNPs containing DLinDAP, DLinDMA, DLinK-DMA, and DLinKC2-DMA (cationic lipid:DSPC:CHOL: PEGS-DMG or PEG-C-DOMG at 40:10:40:10 molar ratios). When required, 0.2% SP-DiOC18 (Invitrogen, Burlington, Canada) may be incorporated to assess cellular uptake, intracellular delivery, and biodistribution. Encapsulation may be performed by dissolving lipid mixtures comprised of cationic lipid:DSPC:cholesterol:PEG-c-DOMG (40:10:40:10 molar ratio) in ethanol to a final lipid concentration of 10 mmol/1. This ethanol solution of lipid may be added drop-wise to 50 mmol/1 citrate, pH 4.0 to form multilamellar vesicles to produce a final concentration of 30% ethanol vol/vol. Large unilamellar vesicles may be formed following extrusion of multilamellar vesicles through two stacked 80 nm Nuclepore polycarbonate filters using the Extruder (Northern Lipids, Vancouver, Canada). Encapsulation may be achieved by adding RNA dissolved at 2 mg/ml in 50 mmol/1 citrate, pH 4.0 containing 30% ethanol vol/vol drop-wise to extruded preformed large unilamellar vesicles and incubation at 31° C. for 30 minutes with constant mixing to a final RNA/lipid weight ratio of 0.06/1 wt/wt. Removal of ethanol and neutralization of formulation buffer were performed by dialysis against phosphate-buffered saline (PBS), pH 7.4 for 16 hours using Spectra/Por 2 regenerated cellulose dialysis membranes. Nanoparticle size distribution may be determined by dynamic light scattering using a NICOMP 370 particle sizer, the vesicle/intensity modes, and Gaussian fitting (Nicomp Particle Sizing, Santa Barbara, Calif.). The particle size for all three LNP systems may be ˜70 nm in diameter. RNA encapsulation efficiency may be determined by removal of free RNA using VivaPureD MiniH columns (Sartorius Stedim Biotech) from samples collected before and after dialysis. The encapsulated RNA may be extracted from the eluted nanoparticles and quantified at 260 nm. RNA to lipid ratio was determined by measurement of cholesterol content in vesicles using the Cholesterol E enzymatic assay from Wako Chemicals USA (Richmond, Va.). In conjunction with the herein discussion of LNPs and PEG lipids, PEGylated liposomes or LNPs are likewise suitable for delivery of a CRISPR-Cas system or components thereof

Preparation of large LNPs may be used/and or adapted from Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011. A lipid premix solution (20.4 mg/ml total lipid concentration) may be prepared in ethanol containing DLinKC2-DMA, DSPC, and cholesterol at 50:10:38.5 molar ratios. Sodium acetate may be added to the lipid premix at a molar ratio of 0.75:1 (sodium acetate:DLinKC2-DMA). The lipids may be subsequently hydrated by combining the mixture with 1.85 volumes of citrate buffer (10 mmol/1, pH 3.0) with vigorous stirring, resulting in spontaneous liposome formation in aqueous buffer containing 35% ethanol. The liposome solution may be incubated at 37° C. to allow for time-dependent increase in particle size. Aliquots may be removed at various times during incubation to investigate changes in liposome size by dynamic light scattering (Zetasizer Nano ZS, Malvern Instruments, Worcestershire, UK). Once the desired particle size is achieved, an aqueous PEG lipid solution (stock=10 mg/ml PEG-DMG in 35% (vol/vol) ethanol) may be added to the liposome mixture to yield a final PEG molar concentration of 3.5% of total lipid. Upon addition of PEG-lipids, the liposomes should their size, effectively quenching further growth. RNA may then be added to the empty liposomes at an RNA to total lipid ratio of approximately 1:10 (wt:wt), followed by incubation for 30 minutes at 37° C. to form loaded LNPs. The mixture may be subsequently dialyzed overnight in PBS and filtered with a 0.45-μm syringe filter.

Preassembled recombinant CRISPR-Cpf1 complexes comprising Cpf1 and crRNA may be transfected, for example by electroporation, resulting in high mutation rates and absence of detectable off-target mutations. Hur, J. K. et al, Targeted mutagenesis in mice by electroporation of Cpf1 ribonucleoproteins, Nat Biotechnol. 2016 Jun. 6. doi: 10.1038/nbt.3596. [Epub ahead of print]

In terms of local delivery to the brain, this can be achieved in various ways. For instance, material can be delivered intrastriatally e.g. by injection. Injection can be performed stereotactically via a craniotomy.

Enhancing NHEJ or HR efficiency is also helpful for delivery. It is preferred that NHEJ efficiency is enhanced by co-expressing end-processing enzymes such as Trex2 (Dumitrache et al. Genetics. 2011 August; 188(4): 787-797). It is preferred that HR efficiency is increased by transiently inhibiting NHEJ machineries such as Ku70 and Ku86. HR efficiency can also be increased by co-expressing prokaryotic or eukaryotic homologous recombination enzymes such as RecBCD, RecA.

In some embodiments, sugar-based particles may be used, for example GalNAc, as described herein and with reference to WO2014118272 (incorporated herein by reference) and Nair, J K et al., 2014, Journal of the American Chemical Society 136 (49), 16958-16961) and the teaching herein, especially in respect of delivery applies to all particles unless otherwise apparent. This may be considered to be a sugar-based particle and further details on other particle delivery systems and/or formulations are provided herein. GalNAc can therefore be considered to be a particle in the sense of the other particles described herein, such that general uses and other considerations, for instance delivery of said particles, apply to GalNAc particles as well. A solution-phase conjugation strategy may for example be used to attach triantennary GalNAc clusters (mol. wt. ˜2000) activated as PFP (pentafluorophenyl) esters onto 5′-hexylamino modified oligonucleotides (5′-HA ASOs, mol. wt. ˜8000 Da; Østergaard et al., Bioconjugate Chem., 2015, 26 (8), pp 1451-1455). Similarly, poly(acrylate) polymers have been described for in vivo nucleic acid delivery (see WO2013158141 incorporated herein by reference). In further alternative embodiments, pre-mixing CRISPR nanoparticles (or protein complexes) with naturally occurring serum proteins may be used in order to improve delivery (Akinc A et al, 2010, Molecular Therapy vol. 18 no. 7, 1357-1364).

Nanoclews

Further, the CRISPR system may be delivered using nanoclews, for example as described in Sun W et al, Cocoon - like self - degradable DNA nanoclew for anticancer drug delivery ., J Am Chem Soc. 2014 Oct. 22; 136(42):14722-5. doi: 10.1021/ja5088024. Epub 2014 Oct. 13. ; or in Sun W et al, Self - Assembled DNA Nanoclews for the Efficient Delivery of CRISPR - Cas 9 for Genome Editing ., Angew Chem Int Ed Engl. 2015 Oct. 5; 54(41):12029-33. doi: 10.1002/anie.201506030. Epub 2015 Aug. 27.

In some embodiments, delivery is by encapsulation of the Cpf1 protein or mRNA form in a lipid particle such as an LNP. In some embodiments, therefore, lipid nanoparticles (LNPs) are contemplated. An antitransthyretin small interfering RNA has been encapsulated in lipid nanoparticles and delivered to humans (see, e.g., Coelho et al., N Engl J Med 2013; 369:819-29), and such a system may be adapted and applied to the CRISPR-Cas system of the present invention. Doses of about 0.01 to about 1 mg per kg of body weight administered intravenously are contemplated. Medications to reduce the risk of infusion-related reactions are contemplated, such as dexamethasone, acetampinophen, diphenhydramine or cetirizine, and ranitidine are contemplated. Multiple doses of about 0.3 mg per kilogram every 4 weeks for five doses are also contemplated.

LNPs have been shown to be highly effective in delivering siRNAs to the liver (see, e.g., Tabernero et al., Cancer Discovery, April 2013, Vol. 3, No. 4, pages 363-470) and are therefore contemplated for delivering RNA encoding CRISPR-Cas to the liver. A dosage of about four doses of 6 mg/kg of the LNP every two weeks may be contemplated. Tabernero et al. demonstrated that tumor regression was observed after the first 2 cycles of LNPs dosed at 0.7 mg/kg, and by the end of 6 cycles the patient had achieved a partial response with complete regression of the lymph node metastasis and substantial shrinkage of the liver tumors. A complete response was obtained after 40 doses in this patient, who has remained in remission and completed treatment after receiving doses over 26 months. Two patients with RCC and extrahepatic sites of disease including kidney, lung, and lymph nodes that were progressing following prior therapy with VEGF pathway inhibitors had stable disease at all sites for approximately 8 to 12 months, and a patient with PNET and liver metastases continued on the extension study for 18 months (36 doses) with stable disease.

However, the charge of the LNP must be taken into consideration. As cationic lipids combined with negatively charged lipids to induce nonbilayer structures that facilitate intracellular delivery. Because charged LNPs are rapidly cleared from circulation following intravenous injection, ionizable cationic lipids with pKa values below 7 were developed (see, e.g., Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). Negatively charged polymers such as RNA may be loaded into LNPs at low pH values (e.g., pH 4) where the ionizable lipids display a positive charge. However, at physiological pH values, the LNPs exhibit a low surface charge compatible with longer circulation times. Four species of ionizable cationic lipids have been focused upon, namely 1,2-dilineoyl-3-dimethylammonium-propane (DLinDAP), 1,2-dilinoleyloxy-3-N,N-dimethylaminopropane (DLinDMA), 1,2-dilinoleyloxy-keto-N,N-dimethyl-3-aminopropane (DLinKDMA), and 1,2-dilinoleyl-4-(2-dimethylaminoethyl)-[1,3]-dioxolane (DLinKC2-DMA). It has been shown that LNP siRNA systems containing these lipids exhibit remarkably different gene silencing properties in hepatocytes in vivo, with potencies varying according to the series DLinKC2-DMA>DLinKDMA>DLinDMA>>DLinDAP employing a Factor VII gene silencing model (see, e.g., Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). A dosage of 1 μg/ml of LNP or CRISPR-Cas RNA in or associated with the LNP may be contemplated, especially for a formulation containing DLinKC2-DMA.

Preparation of LNPs and CRISPR-Cas encapsulation may be used/and or adapted from Rosin et al, Molecular Therapy, vol. 19, no. 12, pages 1286-2200, December 2011). The cationic lipids 1,2-dilineoyl-3-dimethylammonium-propane (DLinDAP), 1,2-dilinoleyloxy-3-N,N-dimethylaminopropane (DLinDMA), 1,2-dilinoleyloxyketo-N,N-dimethyl-3-aminopropane (DLinK-DMA), 1,2-dilinoleyl-4-(2-dimethylaminoethyl)-[1,3]-dioxolane (DLinKC2-DMA), (3-o-[2″-(methoxypolyethyleneglycol 2000) succinoyl]-1,2-dimyristoyl-sn-glycol (PEG-S-DMG), and R-3-1(ω-methoxy-poly(ethylene glycol)2000) carbamoyl]-1,2-dimyristyloxlpropyl-3-amine (PEG-C-DOMG) may be provided by Tekmira Pharmaceuticals (Vancouver, Canada) or synthesized. Cholesterol may be purchased from Sigma (St Louis, Mo.). The specific CRISPR-Cas RNA may be encapsulated in LNPs containing DLinDAP, DLinDMA, DLinK-DMA, and DLinKC2-DMA (cationic lipid:DSPC:CHOL: PEGS-DMG or PEG-C-DOMG at 40:10:40:10 molar ratios). When required, 0.2% SP-DiOC18 (Invitrogen, Burlington, Canada) may be incorporated to assess cellular uptake, intracellular delivery, and biodistribution. Encapsulation may be performed by dissolving lipid mixtures comprised of cationic lipid:DSPC:cholesterol:PEG-c-DOMG (40:10:40:10 molar ratio) in ethanol to a final lipid concentration of 10 mmol/1. This ethanol solution of lipid may be added drop-wise to 50 mmol/1 citrate, pH 4.0 to form multilamellar vesicles to produce a final concentration of 30% ethanol vol/vol. Large unilamellar vesicles may be formed following extrusion of multilamellar vesicles through two stacked 80 nm Nuclepore polycarbonate filters using the Extruder (Northern Lipids, Vancouver, Canada). Encapsulation may be achieved by adding RNA dissolved at 2 mg/ml in 50 mmol/1 citrate, pH 4.0 containing 30% ethanol vol/vol drop-wise to extruded preformed large unilamellar vesicles and incubation at 31° C. for 30 minutes with constant mixing to a final RNA/lipid weight ratio of 0.06/1 wt/wt. Removal of ethanol and neutralization of formulation buffer were performed by dialysis against phosphate-buffered saline (PBS), pH 7.4 for 16 hours using Spectra/Por 2 regenerated cellulose dialysis membranes. Nanoparticle size distribution may be determined by dynamic light scattering using a NICOMP 370 particle sizer, the vesicle/intensity modes, and Gaussian fitting (Nicomp Particle Sizing, Santa Barbara, Calif.). The particle size for all three LNP systems may be ˜70 nm in diameter. RNA encapsulation efficiency may be determined by removal of free RNA using VivaPureD MiniH columns (Sartorius Stedim Biotech) from samples collected before and after dialysis. The encapsulated RNA may be extracted from the eluted nanoparticles and quantified at 260 nm. RNA to lipid ratio was determined by measurement of cholesterol content in vesicles using the Cholesterol E enzymatic assay from Wako Chemicals USA (Richmond, Va.). In conjunction with the herein discussion of LNPs and PEG lipids, PEGylated liposomes or LNPs are likewise suitable for delivery of a CRISPR-Cas system or components thereof

A lipid premix solution (20.4 mg/ml total lipid concentration) may be prepared in ethanol containing DLinKC2-DMA, DSPC, and cholesterol at 50:10:38.5 molar ratios. Sodium acetate may be added to the lipid premix at a molar ratio of 0.75:1 (sodium acetate:DLinKC2-DMA). The lipids may be subsequently hydrated by combining the mixture with 1.85 volumes of citrate buffer (10 mmol/1, pH 3.0) with vigorous stirring, resulting in spontaneous liposome formation in aqueous buffer containing 35% ethanol. The liposome solution may be incubated at 37° C. to allow for time-dependent increase in particle size. Aliquots may be removed at various times during incubation to investigate changes in liposome size by dynamic light scattering (Zetasizer Nano ZS, Malvern Instruments, Worcestershire, UK). Once the desired particle size is achieved, an aqueous PEG lipid solution (stock=10 mg/ml PEG-DMG in 35% (vol/vol) ethanol) may be added to the liposome mixture to yield a final PEG molar concentration of 3.5% of total lipid. Upon addition of PEG-lipids, the liposomes should their size, effectively quenching further growth. RNA may then be added to the empty liposomes at an RNA to total lipid ratio of approximately 1:10 (wt:wt), followed by incubation for 30 minutes at 37° C. to form loaded LNPs. The mixture may be subsequently dialyzed overnight in PBS and filtered with a 0.45-μm syringe filter.

Spherical Nucleic Acid (SNA™) constructs and other nanoparticles (particularly gold nanoparticles) are also contemplated as a means to delivery CRISPR-Cas system to intended targets. Significant data show that AuraSense Therapeutics' Spherical Nucleic Acid (SNA™) constructs, based upon nucleic acid-functionalized gold nanoparticles, are useful.

Literature that may be employed in conjunction with herein teachings include: Cutler et al., J. Am. Chem. Soc. 2011 133:9254-9257, Hao et al., Small. 2011 7:3158-3162, Zhang et al., ACS Nano. 2011 5:6962-6970, Cutler et al., J. Am. Chem. Soc. 2012 134:1376-1391, Young et al., Nano Lett. 2012 12:3867-71, Zheng et al., Proc. Natl. Acad. Sci. USA. 2012 109:11975-80, Mirkin, Nanomedicine 2012 7:635-638 Zhang et al., J. Am. Chem. Soc. 2012 134:16488-1691, Weintraub, Nature 2013 495:S14-S16, Choi et al., Proc. Natl. Acad. Sci. USA. 2013 110(19):7625-7630, Jensen et al., Sci. Transl. Med. 5, 209ra152 (2013) and Mirkin, et al., Small, 10:186-192.

Self-assembling nanoparticles with RNA may be constructed with polyethyleneimine (PEI) that is PEGylated with an Arg-Gly-Asp (RGD) peptide ligand attached at the distal end of the polyethylene glycol (PEG). This system has been used, for example, as a means to target tumor neovasculature expressing integrins and deliver siRNA inhibiting vascular endothelial growth factor receptor-2 (VEGF R2) expression and thereby achieve tumor angiogenesis (see, e.g., Schiffelers et al., Nucleic Acids Research, 2004, Vol. 32, No. 19). Nanoplexes may be prepared by mixing equal volumes of aqueous solutions of cationic polymer and nucleic acid to give a net molar excess of ionizable nitrogen (polymer) to phosphate (nucleic acid) over the range of 2 to 6. The electrostatic interactions between cationic polymers and nucleic acid resulted in the formation of polyplexes with average particle size distribution of about 100 nm, hence referred to here as nanoplexes. A dosage of about 100 to 200 mg of CRISPR-Cas is envisioned for delivery in the self-assembling nanoparticles of Schiffelers et al.

The nanoplexes of Bartlett et al. (PNAS, Sep. 25, 2007,vol. 104, no. 39) may also be applied to the present invention. The nanoplexes of Bartlett et al. are prepared by mixing equal volumes of aqueous solutions of cationic polymer and nucleic acid to give a net molar excess of ionizable nitrogen (polymer) to phosphate (nucleic acid) over the range of 2 to 6. The electrostatic interactions between cationic polymers and nucleic acid resulted in the formation of polyplexes with average particle size distribution of about 100 nm, hence referred to here as nanoplexes. The DOTA-siRNA of Bartlett et al. was synthesized as follows: 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono(N-hydroxysuccinimide ester) (DOTA-NHSester) was ordered from Macrocyclics (Dallas, Tex.). The amine modified RNA sense strand with a 100-fold molar excess of DOTA-NHS-ester in carbonate buffer (pH 9) was added to a microcentrifuge tube. The contents were reacted by stirring for 4 h at room temperature. The DOTA-RNAsense conjugate was ethanol-precipitated, resuspended in water, and annealed to the unmodified antisense strand to yield DOTA-siRNA. All liquids were pretreated with Chelex-100 (Bio-Rad, Hercules, Calif.) to remove trace metal contaminants. Tf-targeted and nontargeted siRNA nanoparticles may be formed by using cyclodextrin-containing polycations. Typically, nanoparticles were formed in water at a charge ratio of 3 (+/−) and an siRNA concentration of 0.5 g/liter. One percent of the adamantane-PEG molecules on the surface of the targeted nanoparticles were modified with Tf (adamantane-PEG-Tf). The nanoparticles were suspended in a 5% (wt/vol) glucose carrier solution for injection.

Davis et al. (Nature, Vol 464, 15 Apr. 2010) conducts a RNA clinical trial that uses a targeted nanoparticle-delivery system (clinical trial registration number NCT00689065). Patients with solid cancers refractory to standard-of-care therapies are administered doses of targeted nanoparticles on days 1, 3, 8 and 10 of a 21-day cycle by a 30-min intravenous infusion. The nanoparticles consist of a synthetic delivery system containing: (1) a linear, cyclodextrin-based polymer (CDP), (2) a human transferrin protein (TF) targeting ligand displayed on the exterior of the nanoparticle to engage TF receptors (TFR) on the surface of the cancer cells, (3) a hydrophilic polymer (polyethylene glycol (PEG) used to promote nanoparticle stability in biological fluids), and (4) siRNA designed to reduce the expression of the RRM2 (sequence used in the clinic was previously denoted siR2B+5). The TFR has long been known to be upregulated in malignant cells, and RRM2 is an established anti-cancer target. These nanoparticles (clinical version denoted as CALAA-01) have been shown to be well tolerated in multi-dosing studies in non-human primates. Although a single patient with chronic myeloid leukaemia has been administered siRNA by liposomal delivery, Davis et al.'s clinical trial is the initial human trial to systemically deliver siRNA with a targeted delivery system and to treat patients with solid cancer. To ascertain whether the targeted delivery system can provide effective delivery of functional siRNA to human tumors, Davis et al. investigated biopsies from three patients from three different dosing cohorts; patients A, B and C, all of whom had metastatic melanoma and received CALAA-01 doses of 18, 24 and 30 mg m-2 siRNA, respectively. Similar doses may also be contemplated for the CRISPR-Cas system of the present invention. The delivery of the invention may be achieved with nanoparticles containing a linear, cyclodextrin-based polymer (CDP), a human transferrin protein (TF) targeting ligand displayed on the exterior of the nanoparticle to engage TF receptors (TFR) on the surface of the cancer cells and/or a hydrophilic polymer (for example, polyethylene glycol (PEG) used to promote nanoparticle stability in biological fluids).

U.S. Pat. No. 8,709,843, incorporated herein by reference, provides a drug delivery system for targeted delivery of therapeutic agent-containing particles to tissues, cells, and intracellular compartments. The invention provides targeted particles comprising polymer conjugated to a surfactant, hydrophilic polymer or lipid.

U.S. Pat. No. 6,007,845, incorporated herein by reference, provides particles which have a core of a multiblock copolymer formed by covalently linking a multifunctional compound with one or more hydrophobic polymers and one or more hydrophilic polymers, and contain a biologically active material.

U.S. Pat. No. 5,855,913, incorporated herein by reference, provides a particulate composition having aerodynamically light particles having a tap density of less than 0.4 g/cm3 with a mean diameter of between 5 μm and 30 μm, incorporating a surfactant on the surface thereof for drug delivery to the pulmonary system.

U.S. Pat. No. 5,985,309, incorporated herein by reference, provides particles incorporating a surfactant and/or a hydrophilic or hydrophobic complex of a positively or negatively charged therapeutic or diagnostic agent and a charged molecule of opposite charge for delivery to the pulmonary system.

U.S. Pat. No. 5,543,158, incorporated herein by reference, provides biodegradable injectable particles having a biodegradable solid core containing a biologically active material and poly(alkylene glycol) moieties on the surface.

WO2012135025 (also published as US20120251560), incorporated herein by reference, describes conjugated polyethyleneimine (PEI) polymers and conjugated aza-macrocycles (collectively referred to as “conjugated lipomer” or “lipomers”). In certain embodiments, it can envisioned that such conjugated lipomers can be used in the context of the CRISPR-Cas system to achieve in vitro, ex vivo and in vivo genomic perturbations to modify gene expression, including modulation of protein expression.

In one embodiment, the nanoparticle may be epoxide-modified lipid-polymer, advantageously 7C1 (see, e.g., James E. Dahlman and Carmen Barnes et al. Nature Nanotechnology (2014) published online 11 May 2014, doi:10.1038/nnano 2014.84). C71 was synthesized by reacting C15 epoxide-terminated lipids with PEI600 at a 14:1 molar ratio, and was formulated with C14PEG2000 to produce nanoparticles (diameter between 35 and 60 nm) that were stable in PBS solution for at least 40 days.

An epoxide-modified lipid-polymer may be utilized to deliver the CRISPR-Cas system of the present invention to pulmonary, cardiovascular or renal cells, however, one of skill in the art may adapt the system to deliver to other target organs. Dosage ranging from about 0.05 to about 0.6 mg/kg are envisioned. Dosages over several days or weeks are also envisioned, with a total dosage of about 2 mg/kg.

In some embodiments, the LNP for deliverting the RNA molecules is prepared by methods known in the art, such as those described in, for example, WO 2005/105152 (PCT/EP2005/004920), WO 2006/069782 (PCT/EP2005/014074), WO 2007/121947 (PCT/EP2007/003496), and WO 2015/082080 (PCT/EP2014/003274), which are herein incorporated by reference. LNPs aimed specifically at the enhanced and improved delivery of siRNA into mammalian cells are described in, for example, Aleku et al., Cancer Res., 68(23): 9788-98 (Dec. 1, 2008), Strumberg et al., Int. J. Clin. Pharmacol. Ther., 50(1): 76-8 (January 2012), Schultheis et al., J. Clin. Oncol., 32(36): 4141-48 (Dec. 20, 2014), and Fehring et al., Mol. Ther., 22(4): 811-20 (Apr. 22, 2014), which are herein incorporated by reference and may be applied to the present technology.

In some embodiments, the LNP includes any LNP disclosed in WO 2005/105152 (PCT/EP2005/004920), WO 2006/069782 (PCT/EP2005/014074), WO 2007/121947 (PCT/EP2007/003496), and WO 2015/082080 (PCT/EP2014/003274).

In some embodiments, the LNP includes at least one lipid having Formula I:

wherein R1 and R2 are each and independently selected from the group comprising alkyl, n is any integer between 1 and 4, and R3 is an acyl selected from the group comprising lysyl, ornithyl, 2,4-diaminobutyryl, histidyl and an acyl moiety according to Formula II:

wherein m is any integer from 1 to 3 and Y − is a pharmaceutically acceptable anion. In some embodiments, a lipid according to Formula I includes at least two asymmetric C atoms. In some embodiments, enantiomers of Formula I include, but are not limited to, R-R; S-S; R—S and S-R enantiomer.

In some embodiments, R1 is lauryl and R2 is myristyl. In another embodiment, R1 is palmityl and R2 is oleyl. In some embodiments, m is 1 or 2. In some embodiments, Y- is selected from halogenids, acetate or trifluoroacetate.

In some embodiments, the LNP comprises one or more lipids select from:

β-arginyl-2,3-diamino propionic acid-N-palmityl-N-oleyl-amide trihydrochloride (Formula III):

β-arginyl-2,3-diamino propionic acid-N-lauryl-N-myristyl-amide trihydrochloride (Formula IV):

and

ε-arginyl-lysine-N-lauryl-N-myristyl-amide trihydrochloride (Formula V):

In some embodiments, the LNP also includes a constituent. By way of example, but not by way of limitation, in some embodiments, the constituent is selected from peptides, proteins, oligonucleotides, polynucleotides, nucleic acids, or a combination thereof. In some embodiments, the constituent is an antibody, e.g., a monoclonal antibody. In some embodiments, the constituent is a nucleic acid selected from, e.g., ribozymes, aptamers, spiegelmers, DNA, RNA, PNA, LNA, or a combination thereof. In some embodiments, the nucleic acid is gRNA and/or mRNA.

In some embodiments, the constituent of the LNP comprises an mRNA encoding a CRISPR effector protein. In some embodiments, the constituent of the LNP comprises an mRNA encoding a Type-II, Type-V, or Type-VI CRISPR effector protein. In some embodiments, the constituent of the LNP comprises an mRNA encoding an RNA-guided DNA binding protein. In some embodiments, the constituent of the LNP comprises an mRNA encoding an RNA-guided RNA binding protein.

In some embodiments, the constituent of the LNP further comprises one or more guide RNA. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to vascular endothelium. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to pulmonary endothelium. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to liver. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to lung. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to hearts. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to spleen. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to kidney. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to pancreas. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to brain. In some embodiments, the LNP is configured to deliver the aforementioned mRNA and guide RNA to macrophages.

In some embodiments, the LNP also includes at least one helper lipid. In some embodiments, the helper lipid is selected from phospholipids and steroids. In some embodiments, the phospholipids are di- and/or monoester of the phosphoric acid. In some embodiments, the phospholipids are phosphoglycerides and/or sphingolipids. In some embodiments, the steroids are naturally occurring and/or synthetic compounds based on the partially hydrogenated cyclopenta[alphenanthrene. In some embodiments, the steroids contain 21 to 30 C atoms. In some embodiments, the steroid is cholesterol. In some embodiments, the helper lipid is selected from 1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine (DPhyPE), ceramide, and 1,2-dioleyl-sn-glycero-3-phosphoethanolamine (DOPE).

In some embodiments, the at least one helper lipid comprises a moiety selected from the group comprising a PEG moiety, a HEG moiety, a polyhydroxyethyl starch (polyHES) moiety and a polypropylene moiety. In some embodiments, the moiety has a molecule weight between about 500 to 10,000 Da or between about 2,000 to 5,000 Da. In some embodiments, the PEG moiety is selected from 1,2-distearoyl-sn-glycero-3 phosphoethanolamine, 1,2-dialkyl-sn-glycero-3-phosphoethanolamine, and Ceramide-PEG. In some embodiments, the PEG moiety has a molecular weight between about 500 to 10,000 Da or between about 2,000 to 5,000 Da. In some embodiments, the PEG moiety has a molecular weight of 2,000 Da.

In some embodiments, the helper lipid is between about 20 mol % to 80 mol % of the total lipid content of the composition. In some embodiments, the helper lipid component is between about 35 mol % to 65 mol % of the total lipid content of the LNP. In some embodiments, the LNP includes lipids at 50 mol % and the helper lipid at 50 mol % of the total lipid content of the LNP.

In some embodiments, the LNP includes any of -3-arginyl-2,3-diaminopropionic acid-N-palmityl-N-oleyl-amide trihydrochloride, -arginyl-2,3-diaminopropionic acid-N-lauryl-N-myristyl-amide trihydrochloride or arginyl-lysine-N-lauryl-N-myristyl-amide trihydrochloride in combination with DPhyPE, wherein the content of DPhyPE is about 80 mol %, 65 mol %, 50 mol % and 35 mol % of the overall lipid content of the LNP. In some embodiments, the LNP includes -arginyl-2,3-diamino propionic acid-N-pahnityl-N-oleyl-amide trihydrochloride (lipid) and 1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine (helper lipid). In some embodiments, the LNP includes -arginyl-2,3-diamino propionic acid-N-palmityl-N-oleyl-amide trihydrochloride (lipid), 1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine (first helper lipid), and 1,2-disteroyl-sn-glycero-3-phosphoethanolam